NIST Final WTC7 Report News Archives

8:15 a.m. - Report Due on 9/11 Building Collapse

http://arkansasmatters.com/content/f...ws/?cid=102561

Reported by: RNS
Thursday, Aug 21, 2008 @08:15am CST

A report will be presented Thursday by the U.S. Commerce Department's National Institute of Standards and Technology regarding the collapse of World Trade Center Building 7 during the terror attacks of September 11, 2001.

The report on its findings and recommendations from its building and fire safety probe will be unveiled in Gaithersburg, Maryland.

WTC-7 was a 47-story building that collapsed nearly seven hours after the World Trade Center towers went down.

The report will identify the probable collapse sequence for the building and will recommend ways that building and fire safety in similar structures can be enhanced.

The original building was replaced with the new 7 World Trade Center which opened in 2006.

It's 52 stories tall and its design emphasizes safety, with a reinforced concrete core and thicker fireproofing of steel columns.

Fed gov't finds fires took down building next to twin towers

http://www.examiner.com/a-1548037~Fe...in_towers.html

By DEVLIN BARRETT, AP
8/21/2008

GAITHERSBURG, Md. (Map, News) - Government investigators have issued a report refuting conspiracy theories that a skyscraper next to the twin towers was brought down by explosives. The report says that fires destroyed World Trade Center 7 on Sept. 11.

Scientists with the National Institute of Standards and Technology say their three-year investigation of the collapse of the 47-story building was the first known instance of fire causing the total failure of a skyscraper.

The investigators also conclude that the collapse of the nearby twin towers broke the city water main, leaving the sprinkler system in WTC 7 without water.

The collapse of building 7 has long been the subject of conspiracy theories that something else brought down the tower.

NIST WTC 7 Investigation Finds Building Fires Caused Collapse

Report and Recommendations for Improving Building Safety Released for Comment

http://www.nist.gov/public_affairs/r...wtc082108.html

8/21/2008

GAITHERSBURG, Md.—The fall of the 47-story World Trade Center building 7 (WTC 7) in New York City late in the afternoon of Sept. 11, 2001, was primarily due to fires, the Commerce Department’s National Institute of Standards and Technology (NIST) announced today following an extensive, three-year scientific and technical building and fire safety investigation. This was the first known instance of fire causing the total collapse of a tall building, the agency stated as it released for public comment its WTC investigation report and 13 recommendations for improving building and fire safety.

“Our study found that the fires in WTC 7, which were uncontrolled but otherwise similar to fires experienced in other tall buildings, caused an extraordinary event,” said NIST WTC Lead Investigator Shyam Sunder. “Heating of floor beams and girders caused a critical support column to fail, initiating a fire-induced progressive collapse that brought the building down.”

“Video and photographic evidence combined with detailed computer simulations show that neither explosives nor fuel oil fires played a role in the collapse of WTC 7,” Sunder said. The NIST investigation team also determined that other elements of the building’s construction—namely trusses, girders and cantilever overhangs that were used to transfer loads from the building superstructure to the columns of the electric substation (over which WTC 7 was constructed) and foundation below—did not play a significant role in the collapse.

According to the report, a key factor leading to the eventual collapse of WTC 7 was thermal expansion of long-span floor systems at temperatures “hundreds of degrees below those typically considered in current practice for fire resistance ratings." WTC 7 used a structural system design in widespread use.

Citing its one new recommendation (the other 12 are reiterated from the previously completed investigation of the World Trade Center towers, WTC 1 and 2), the NIST investigation team said that “while the partial or total collapse of a tall building due to fires is a rare event, we strongly urge building owners, operators and designers to evaluate buildings to ensure the adequate fire performance of the structural system. Of particular concern are the effects of thermal expansion in buildings with one or more of the following features: long-span floor systems, connections not designed for thermal effects, asymmetric floor framing and/or composite floor systems.” Engineers, the team said, should be able to design cost-effective fixes to address any areas of concern identified by such evaluations.

The investigators also reported that if the city water main had not been cut by the collapse of World Trade Center towers 1 and 2 (WTC 1 and WTC 2), operating sprinklers in WTC 7 would likely have prevented its collapse. “Nevertheless,” Sunder said, “we recommend that building standards and codes be strengthened beyond their current intent to achieve life safety by preventing structural collapse even during severe fires like this one, when sprinklers do not function, do not exist or are overwhelmed by fire.”

Sunder identified several existing, emerging or even anticipated capabilities that could have helped prevent WTC 7’s collapse. He cautioned that the degree to which these capabilities improve performance remains to be evaluated. Possible options for developing cost-effective fixes include:

• More robust connections and framing systems to better resist effects of thermal expansion on the structural system.
• Structural systems expressly designed to prevent progressive collapse, which is the spread of local damage from a single initiating event, from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it. Current model building codes do not require that buildings be designed to resist progressive collapse.
• Better thermal insulation (i.e., reduced conductivity and/or increased thickness) to limit heating of structural steel and to minimize both thermal expansion and weakening effects. Insulation has been used to protect steel strength, but it could be used to maintain a lower temperature in the steel framing to limit thermal expansion.
• Improved compartmentation in tenant areas to limit the spread of fires.
• Thermally resistant window assemblies to limit breakage, reduce air supply and retard fire growth.

The 12 recommendations reiterated from the WTC towers investigation address several areas, including specific improvements to building standards, codes and practices; changes to, or the establishment of, evacuation and emergency response procedures; and research and other appropriate actions needed to help prevent future building failures.

Determining the probable collapse sequence for WTC 7, NIST found that the impact of debris from the collapse of WTC 1 ignited fires on at least 10 floors of WTC 7, and the fires burned out of control on six lower floors. The heat from these uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors. Eventually, a girder on Floor 13 lost its connection to a critical interior column that provided support for the long floor spans on the east side of the building. The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the fifth floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of the critical column. This collapse of floors left the critical column unsupported over nine stories.

“When this critical column buckled due to lack of floor supports, it was the first domino in the chain,” Sunder explained. “What followed in rapid succession was a progression of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the most eastern side of the building. Then, progressing from east to west across WTC 7, all of the columns in the core of the building failed. Finally, the entire façade collapsed.”

http://www.nist.gov/public_affairs/r.../wtc082108.jpg

Diagram 1—Typical WTC 7 floor showing locations of columns (numbered). The buckling of Column 79 was the initiating event that led to the collapse of WTC 7. The buckling resulted from fire-induced damage to floors around Column 79, failure of the girder between Columns 44 and 79, and cascading floor failures. [Download high-res version]

The investigation team considered the possibility of other factors playing a role in the collapse of WTC 7, including the possible use of explosives, fires fed by the fuel supply tanks in and under the building, and damage from the falling debris of WTC 1.

The team said that the smallest blast event capable of crippling the critical column would have produced a “sound level of 130 to 140 decibels at a distance of half a mile,” yet no noise this loud was reported by witnesses or recorded on videos.

As for fuel fires, the team found that they could not have been sustained long enough, could not have generated sufficient heat to fail a critical column, and/or would have produced “large amounts of visible smoke” from Floors 5 and 6, which was not observed.

Finally, the report notes that “while debris impact from the collapse of WTC 1 initiated fires in WTC 7, the resulting structural damage had little effect in causing the collapse of WTC 7.”

The investigation team found that the design of WTC 7 was generally consistent with the New York City building code in effect at the time. The estimated 4,000 occupants of WTC 7 on the morning of Sept. 11 were evacuated without any fatalities or serious injuries.

To reach the conclusions in its report, NIST complemented its in-house expertise with private-sector technical experts; accumulated an extensive collection of documents, photographs and videos related to the WTC events of 9/11; conducted first-person interviews of WTC 7 occupants and emergency responders; analyzed the evacuation and emergency response operations in and around WTC 7; and performed the most complex computer simulations ever conducted to model a building’s response behavior and determine its collapse sequence due to a combination of debris impact damage, fires and a progression of structural failures from local fire-induced damage to collapse initiation, and, ultimately, to global collapse.

NIST welcomes comments on the draft report and recommendations—available online at http://wtc.nist.gov—received by noon Eastern Daylight Time on Sept.15, 2008. Comments (instructions for submission are available at http://wtc.nist.gov) may be submitted via:

• e-mail to wtc@nist.gov;
• fax to (301) 869-6275; or
• surface mail to WTC Technical Information Repository, Attn: Stephen Cauffman, NIST, 100 Bureau Dr., Stop 8611, Gaithersburg, Md. 20899-8610.

The NIST investigation of WTC 7 was conducted under the National Construction Safety Team (NCST) Act, as part of its overall building and fire safety investigation of the World Trade Center disaster. The act gives NIST the responsibility for conducting fact-finding investigations of building failures that resulted in substantial loss of life or that posed significant potential of substantial loss of life. NIST has no regulatory authority under the NCST Act.

As an agency of the U.S. Department of Commerce, NIST promotes U.S. innovation and industrial competitiveness by advancing measurement science, standards and technology in ways that enhance economic security and improve our quality of life.

Feds say fires downed building next to twin towers

http://ap.google.com/article/ALeqM5i...8_BvgD92MPC580

By DEVLIN BARRETT – 15 minutes ago

GAITHERSBURG, Md. (AP) — Federal investigators issued a report Thursday concluding that fires brought down a skyscraper next to New York's twin towers on Sept. 11, refuting conspiracy theorists who have long believed that explosives somehow caused the collapse.

Scientists with the National Institute of Standards and Technology say their three-year investigation of the collapse of the 47-story World Trade Center 7 was the first known instance of fire causing the total failure of a skyscraper.

The investigators also concluded that the collapse of the nearby towers broke the city water main, leaving the sprinkler system in the bottom half of the building without water.

The structure has been the subject of a wide range of conspiracy theories for the last seven years, partly because the collapse happened about seven hours after the twin towers were felled. That fueled theories that something else might have caused the collapse.

Dr. Shyam Sunder, the lead investigator on the project, said his team investigated the possibility that an explosion inside the building brought it down, but found there was no large boom or other noise that would have occurred with such a detonation.

Investigators also concluded there was no evidence that the collapse was caused by fires from a substantial amount of diesel fuel that was stored in the building.

The 77-page report concluded that the weakening of a critical steel support column led the rest of the building to fall apart.

"When this critical column buckled due to lack of floor supports, it was the first domino in the chain," said Sunder.

The NIST investigators issued more than a dozen building recommendations as a result of their inquiry, most of which repeat earlier recommendations from their investigation into the collapse of the two large towers.

In both instances, investigators concluded that extreme heat caused some steel beams to lose strength, causing further failures throughout the buildings until the entire structure succumbed.

The recommendations include building skyscrapers with stronger connections and framing systems to resist the effects of thermal expansion, and structural systems designed to prevent damage to one part of a building from spreading to other parts.

http://www.mlive.com/newsflash/index...ist=washington

http://www.physorg.com/news138546437.html

As federal agency declares 'new phenomenon' downed WTC 7, activists cry foul

http://rawstory.com/news/2008/BREAKI...y_on_0821.html

Stephen C. Webster
Published: Thursday August 21, 2008

According to a federal agency report released Thursday, a "new phenomenon" known as thermal expansion was directly responsible for the mysterious collapse of World Trade Center 7 on Sept. 11, 2001.

This study, posed by the National Institute of Standards and Technology -- a federal scientific agency which promotes technical industrial standards -- marks the first 'official' government theory on the collapse.

The building's demise occurred some seven hours after the twin towers collapsed on Sept. 11, 2001, and has been the source of numerous conspiracy theories key to the "9/11 Truth" movement, most of which argue that the symmetrical, seven-second collapse was brought about by a controlled demolition.

Dr. Shyam Sunder, director of Institute's building and fire research laboratory, oversaw the government's three-year research efforts. The report aims to disprove the controlled demolition argument.

However, Richard Gage, founder of Architects & Engineers for 9/11 Truth and a member of the American Institute of Architects, doesn't believe a word of the theory.

His group, which has swelled to over 400 architectural and engineering professionals, immediately responded to the Institute's claim in a press conference.

"Tons of [molten metal] was found 21 days after the attack," said Gage in an interview with a Vancouver, Canada television station. "Steel doesn't begin to melt until 2,700 degrees, which is much hotter than what these fires could have caused."

"There are holes in this story that you can drive a truck through," Gage added during the press conference. His group asserts that thermite, a steel cutting agent, was used to bring the building down.

Dr. Sunder disagreed.

"We conducted the study without bias, without interference from anyone," said Dr. Sunder. "We have only one single-minded goal in this effort."

While the Institute said it considered the possibility of a controlled demolition taking place at WTC 7, the notion was dismissed due to the absence of any recordings of an explosion sound.

Thermite, however, does not make an explosion sound. And while this was raised to Dr. Sunder in the media's Q&A session, he dismissed it as impossible.

"FEMA found it," said Gage. "Dr. Steven Jones found it, in the dust that landed in the entire area of lower Manhattan. And he finds it in the chunks of previously molten metal [from the towers]."

Specifically, in Appendix C of its World Trade Center Building Performance Study, FEMA claimed:

Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure. A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel... The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified.

Yet, no study of the mysterious sulfur or melted steel was included in the NIST report.

After New York City officials cut off the water main to the tower Sept. 11, 2001, the building's sprinkler system was unable to function, Dr. Sunder said. This allowed fires across 10 floors to burn uncontrolled for nearly seven hours.

The Institute asserts that due to the lack of water supply, an “extraordinary event” occurred, and for the first time ever, steel expanding due to heat from the flames caused columns to separate from structural concrete. Column 79 was the first to fail, according to the report, which brought about a quick succession of failures in adjoining columns.

"Thermal expansion of long-span floor systems" was a critical element in the collapse, said Dr. Sunder. The "kink" seen in the building's penthouse portion in video of the collapse was in-line with the columns which failed first.

"If water had been available, it is likely that sprinklers would have operated and the building may still be here today," he said.

"It looks like they want to wrap-up this investigation and blame [the collapse] on normal office fires," said Gage during counter-conference.

WTC 7's structural system is in "widespread use" in other buildings, he added, insisting that such effects may also be present elsewhere. The Institute's report also includes recommendations for the strengthening of building codes to avoid future thermal expansion-driven collapses.

The collapse of WTC 7 is "no longer a mystery," Dr. Sunder claimed.

The Institute's full report is available at wtc.nist.gov.

Further details from the Architects & Engineers for 9/11 Truth press conference are forthcoming.

Report Says Fire, Not Explosion, Felled 7 W.T.C.

http://www.nytimes.com/2008/08/22/ny...in&oref=slogin

By ERIC LIPTON
Published: August 21, 2008

GAITHERSBURG, Md. — Fires in the 47-story office tower at the edge of the World Trade Center site undermined floor beams and a critical structural column, federal investigators concluded on Thursday, as they attempted to curb still-rampant speculation that explosives caused the building’s collapse on Sept. 11, 2001.

No one died when the tower, 7 World Trade Center, tumbled, as the estimated 4,000 office workers there at the time had evacuated before it gave way, nearly seven hours after the second of the twin towers came down.

But the collapse of 7 World Trade Center — home at the time to branch offices of the Central Intelligence Agency, the Secret Service and the Giuliani administration’s emergency operations center — is cited in hundreds of Web sites and books as perhaps the most compelling evidence that an insider secretly planted explosives, intentionally destroying the tower.

A separate, preliminary report issued in 2002 by the Federal Emergency Management Agency questioned whether diesel fuel tanks installed in the tower to supply emergency generators — including one that powered the Giuliani administration’s emergency “bunker” — might have been to blame.

But Shyam Sunder, the lead investigator from the National Institute of Standards and Technology, based here in suburban Washington, also rejected that theory on Thursday, even as he acknowledged that the collapse had been something of a puzzle.

“Our take-home message today is the reason for the collapse of World Trade Center 7 is no longer a mystery,” Dr. Sunder said at a news conference at the institute’s headquarters. “It did not collapse from explosives or fuel oil fires.”

The institute’s findings were released on Thursday as part of a 915-page report resulting from the work of more than 50 federal investigators and a dozen contractors over three years.

Conspiracy theorists have pointed to the fact that the building fell straight down, instead of tumbling, as proof that that explosives were used to topple it, as well as to bring down the twin towers. A Scripps Howard/Ohio University poll suggested that as many as one in seven Americans believed that theory.

During the last four decades, other towers in New York, Philadelphia and Los Angeles have remained standing through catastrophic blazes that burned out of control for hours because of malfunctioning or nonexistent sprinkler systems. But 7 World Trade Center, which was not struck by a plane, is the first skyscraper in modern times to collapse primarily as a result of a fire. Adding to the suspicion is the fact that in the rush to clean up the site, almost all of the steel remains of the tower were disposed of, leaving investigators in later years with little forensic evidence.

Using videos, photographs and building design documents, the investigators at the National Institute spent the last three years building an elaborate computer model of 7 World Trade Center that they used to test various chains of events to figure out what caused the collapse, Dr. Sunder said.

The investigators determined that debris from the falling twin towers damaged structural columns and ignited fires on at least 10 floors at 7 World Trade Center, which stood about 400 feet north of the twin towers. But the structural damage from the falling debris was not significant enough to threaten the tower’s stability, Dr. Sunder said.

The fires on six of the lower floors burned with particular intensity because the water supply for the sprinkler system had been cut off — the upper floors had a backup water supply — and the Fire Department, devastated by the collapse of the twin towers, stopped trying to fight the blaze.

Normally, fireproofing on a skyscraper should have been sufficient to allow such a blaze to burn itself out and leave the building damaged but still standing. But investigators determined that the heat from the fire caused girders in the steel floor of 7 World Trade Center to expand. As a result, steel beams underneath the floors that provided lateral support for the tower’s structural columns began to buckle or put pressure against the vertical structural columns.

These fires might have been fed partly by the diesel from tanks and a pressurized fuel line, which were on the fifth to the ninth floors, Dr. Sunder said. But the analysis showed that even in the worst case, the diesel fuel-fed fire would not have burned hot enough or long enough to have played a major role in weakening the structure. The investigators determined that the fire that day was fed mainly by office paper and furnishings.

The collapse started when a girder on the 13th floor disconnected from a critical column — listed as Column 79 — that supported a long open floor span, the report said. Once that floor gave way, the floors below it down to the fifth floor also collapsed, although this was not visible from the building’s exterior.

Without lateral support for nine stories, Column 79 buckled, and the floors above gave way all the way up to the roof. Only then did the collapse become visible from the exterior with a penthouse area on the roof first falling in, followed by what looked like the sudden implosion of the tower, Dr. Sunder said.

“The physics is consistent, it is sound, it has been analyzed,” he said.

Skeptics have questioned whether explosives were planted at the three towers at ground zero, as at well the Pentagon, often contending that the Bush administration had planned the catastrophes to provide a justification to invade Iraq and Afghanistan. What started as a small number of such conspiracy theorists ballooned into a movement of sorts, largely fed by Internet sites and homemade videos.

Dr. Sunder said the investigators considered the possibility that explosives were used, but ruled it out because the noise associated with such an explosion would have been 10 times louder than being in front of the speakers at a rock concert, he said, and detectable from as far as a half a mile away. He said that interviews with eyewitnesses and a review of video taken that day provided no evidence of a sound that loud just before the collapse.

The skeptics — including several who attended Thursday’s news conference — were unimpressed. They have long argued that an incendiary material called thermite, made of aluminum powder and a metal oxide, was used to take down the trade center towers, an approach that would not necessarily result in an explosive boom. They also have argued that a sulfur residue found at the World Trade Center site is evidence of an inside job.

Dr. Sunder said the investigators chose not to use the computer model to evaluate whether a thermite-fueled fire might have brought down the tower, since 100 pounds of it would have had to have been stacked directly against the critical column that gave way, which he said they did not believe had occurred.

To the skeptics, it was a glaring omission.

“It is very difficult to find what you are not looking for,” said Shane Geiger, one who had come to Maryland from Texas to quiz Dr. Sunder about his findings, with a bumper sticker on his laptop computer that says, “9-11 was an inside job.”

Dr. Sunder attempted to patiently answer the questions that Mr. Geiger and another obvious critic presented to him during the news conference. Five armed police officers and a bomb-sniffing dog stood guard near the rear of the room.

Dr. Sunder said there were no apparent flaws in 7 World Trade Center’s design that contributed to its collapse and that it met New York City codes. But there are some important lessons for other skyscrapers, he said, as engineers and architects should consider how the heat from fires can cause structural elements, potentially causing a so-called progressive collapse.

Owners of tall buildings with a similar floor design — he could not estimate how many such towers exist in the United States — should immediately consider whether to install reinforcements, he said, and perhaps codes should be changed to address the weakness.

A new, substantially different 7 World Trade Center — now 52 stories — reopened at roughly the same site in 2006. The new building has a number of extra safety features, including wider emergency stairwells and a fire-resistant refuge area on each floor.

Within moments after the news conference ended, leaders of a group called Architects and Engineers for 9/11 Truth held their own telephone conference briefing, dismissing the investigation as flawed.

“How much longer do we have to endure the cover up of how Building 7 was destroyed?” said Richard Gage, a California architect and leader of the group.

Told of the doubts, Dr. Sunder said he could not explain why the skepticism would not die.

“I am really not a psychologist,” he said. “Our job was to come up with the best science.”

6 Debunked 9/11 Conspiracy Claims From Today's NIST Report

http://www.popularmechanics.com/scie...h/4278927.html

By Arianne Cohen
Published on: August 21, 2008

GAITHERSBURG, MD. — Shyam Sunder, the lead investigator on the National Institute of Standards and Technology (NIST) report, responded directly to many conspiracy claims here this morning at his press conference in NIST headquarters in Gaithersburg, Md., which was attended by mainstream media and a handful of conspiracy theorist media, including a representative from InfoWars.com, a Web site that puts forward 9/11 conspiracy theories. Sunder specifically addressed conspiracy claims linked to WTC 7. "Before I tell you what we found, I'd like to tell you what we did not find," Sunder told reporters. "We did not find any evidence that explosives were used to bring the building down. The collapse was also not due to fires from the substantial amount of diesel fuel stored in the buildings."

Here is a summary of some common 9/11 conspiracy theory claims regarding WTC 7, along with NIST's response:

Claim: "No combination of debris damage, fuel-tank explosions and fires could inflict the kind of simultaneous damage to all the building's columns required to make the building implode," says WTC7.net, a Web site dedicated to conspiracy theories. "The precision of such damage required to bring Building 7 down into its footprint was especially great, given the ratio of its height to its width and depth."

NIST report and press conference: Fire did indeed inflict enough column damage to destroy the building through a previously undocumented collapse sequence of thermal expansion. "Anyone who has run a tight jar lid under water to help loosen it knows that the metal expands when it gets hot," Sunder said. "Heat also causes steel to lose strength and stiffness. Thermal expansion occurs at temperatures much lower than those required to reduce steel strength and stiffness." The report found that as WTC 7's steel beams expanded in the heat, numerous structural connections throughout the building failed. That weakened the structure even before the collapse of any vertical columns.

Claim: The shape of the building's tidy pile of wreckage is consistent with a demolition, conspiracy theorists say.

NIST report and press conference: Sunder agrees that the wreckage was tidy and explained why. "If you look at columns 79, 80 and 81 [three of the building's central columns], the floor area that they're carrying is very large—particularly column 79, which was carrying about 2000 sq. ft. of floor area." Column 79 was the first column to fail. "It was an interior column that failed, followed by two more interior columns [80 and 81], then east to west. So what you're seeing is an interior collapse, then to the outside. What you're getting is an impression of a controlled demolition, but it's not."

Claim: The way the building fell was caused by demolition or thermate. (Thermate is thermite mixed with sulfur and sometimes other chemicals, which produces brief but intense and highly localized incendiary effects.)

NIST report and press conference: Sunder said that his team investigated these hypothetical causes and ruled them out. "We asked ourselves what is the minimum amount of charge we could use to bring the building down," he said. "And we found that even the smallest charge would release an extremely loud sound heard half a mile away." There were no reports of such a sound; numerous observers and video recordings found the collapse to be relatively quiet.

Prominent conspiracy theorist Steven Jones and others have suggested that thermate could have been inserted into a column, exploding the column without the loud boom of a demolition. Sunder said his team considered that theory. "In order for the thermate reaction to melt steel to take place, there has to be materials. If you look at the amount needed—at least 100 pounds for one column—you need someone to get that amount in the building, and place it, and for the reaction to take place. It is unlikely."

Claim: At the press conference, theorists questioned why NIST had just now found a previously undocumented cause of building collapse.

NIST report and press conference: The particulars of WTC 7's design contributed to the thermal expansion. WTC 7 had floor spans up to 54 ft. long. "Longer beams can be subject to proportionally greater expansion effects," Sunder noted. "Other tall buildings have burned for as long or longer in similar fires without collapsing—when sprinklers either did not exist or were not functional. So we knew from the beginning of our study that understanding what happened to Building 7 on 9/11 would be difficult. It did not fit any textbook description that you could readily point to and say, yes, that's why the building failed." The issue, Sunder said, was that buildings are not typically tested for their structural response to fire.

Claim: The minimal wreckage available for later investigation has generated speculation. Some conspirators point to the fast removal of debris as evidence of a government coverup.

NIST report and press conference: Compared to WTC 1 and 2, NIST had very little WTC 7 wreckage to study. The site was cleared quickly in a search-an- rescue effort, and much of the debris was transported to salvage yards. "There was no loss of life," Sunder noted. "In hindsight, we knew that the building was evacuated. But we didn't know that on that day." Hundreds of investigators at the salvage yards later found that the Twin Towers' steel columns were labeled and numbered, while the columns from Towers 5, 6 and 7 were not. "I am not surprised that there wasn't a lot of identifiable debris," Sunder said. "But at the time, we were concerned about terrorists who attacked our country and search and rescue. I think the fact that they [invesigators] didn't collect [wreckage] was the least important activity that happened that day."

Claim: Many theorists have suggested that the long delay in an explanatory report is further proof of a government coverup.

NIST and press conference: NIST first had to complete the investigation on the collapse of the Twin Towers and publish its report before turning to WTC 7. The Twin Towers report was released in September 2005. "We thought we might be able to do things much quicker and faster because of our tower experience," Sunder said. "I think we underestimated the amount of effort that would be required to answer the questions that we raised." In addition, new computer models of the collapse had to be created. "A typical fire simulation for a single floor of the building took up to two days with a state-of-the-art cluster of Linux computers. We had computer programs that took six to eight months to get a correct run, and we wanted to make sure we got this right. And three years is not an unusual length of time." Sunder emphasized that previous reports were preliminary and provisional. "We didn't have the insight that thermal expansion could have happened until early last year," Sunder said. "After that it was smooth sailing." Until last year, NIST was still investigating other hypotheses, including whether the building's location on top of an electric substation played a critical role and whether 6000 gal. of diesel fuel used to power backup generators in the building directly weakened the columns. Both hypotheses were abandoned.

Sunder classified the report's conclusions as "simple, straightforward, elegant and going along with what was observed. I would say that the findings we have are incredibly conclusive that fire is why WTC 7 collapsed."

Fire caused collapse of World Trade Center 7: probe

http://afp.google.com/article/ALeqM5...psTpGQ-ORg_Uqw

1 hour ago

NEW YORK (AFP) — A raging, long-burning fire caused the collapse of World Trade Center building number 7, which tumbled hours after hijacked jets hit the twin towers on September 11, 2001, investigators said Thursday.

The National Institute of Standards and Technology (NIST) found that the 47-story building, which stood right next to towers 1 and 2, caught fire due to the debris that flew into it after the planes struck.

It eventually fell after seven hours due to instability caused by the fire, not by explosives as some conspiracy theorists have claimed.

"Our study found that the fires in WTC 7, which were uncontrolled but otherwise similar to fires experienced in other tall buildings, caused an extraordinary event," said lead investigator Shyam Sunder.

"Heating of floor beams and girders caused a critical support column to fail, initiating a fire-induced progressive collapse that brought the building down," he said.

"Video and photographic evidence combined with detailed computer simulations show that neither explosives nor fuel oil fires played a role in the collapse of WTC 7."

He said debris from tower 1 sparked the blaze on at least 10 floors of the building, which burned for about seven hours while some of its sprinkler systems were non-operational due to a city water main cut.

"We did not find any evidence that explosives were used to bring the building down," he said.

"This size blast would have produced an incredibly loud sound that was not recorded on videos of the collapse nor reported by witnesses."

He added that the "collapse was also not due to fires from the substantial amount of diesel fuel stored in the building."

A team of 50 experts from diverse fields, including engineering, explosives, fire, and construction took part in the probe.

The September 11 attacks on New York killed nearly 3,000 people.

Computer modeling confirms cause of 9/11 building collapse

http://www.gcn.com/online/vol1_no1/46958-1.html

By William Jackson
8/21/2008

Using sophisticated computer modeling to reproduce the Sept. 11, 2001, collapse of World Trade Center Building 7, the National Institute of Standards and Technology concluded that it was fire and not explosives or impact from debris that caused the 47-story building to fail.

NIST announced the findings of the three year study Thursday [http://wtc.nist.gov /], and recommended changes in national building codes to take into account the affects of thermal expansion on structural members.

“Our study found that the fires in WTC 7, which were uncontrolled but otherwise similar to fires experienced in other tall buildings, caused an extraordinary event,” said Shyam Sunder, lead investigator in the NIST World Trade Center study. “Heating of floor beams and girders caused a critical support column to fail, initiating a fire-induced progressive collapse that brought the building down.”

Building 7 was the third building to collapse in the World Trade Center attacks. The two iconic towers collapsed shortly after being hit by hijacked airliners that morning. Building 7 was set ablaze by debris from the attacks and collapsed several hours later. NIST began investigating the attacks in August 2002 and released its findings on the collapse of towers 1 and 2 three years later. Investigators spent the last three years investigating Building 7.

“The investigation was an extensive, state-of-the-art reconstruction of the events that affected WTC 7 and eventually led to its collapse,” NIST said. “Numerous facts and data were obtained, then combined with validated computer modeling that is believed to be close to what actually occurred. A single computer simulation of the structural response to fires took about eight months to complete on powerful computing workstations and clusters.”

The investigation was somewhat hampered by the fact that steel samples from the building were not available for examination and testing. Debris from the attacks was removed as quickly as possible from the sites so that emergency responders could work in the area. Once removed from the scene, steel from Building 7 could not be clearly identified. Unlike pieces from the two primary towers, which were painted red and contained distinguishing marks, remains of Building 7 contained nothing to distinguish them.

This meant that there was much less physical evidence to examine from Building 7. “Nonetheless, the NIST investigation of WTC 7 is based on a huge amount of data,” investigators wrote. “These data come from extensive research, interviews, and studies of the building, including audio and video recordings of the collapse. Rigorous, state-of-the-art computer methods were designed to study and model the building’s collapse. These validated computer models produced a collapse sequence that was confirmed by observations of what actually occurred.”

Report: Fire Caused 7 World Trade Center Collapse

http://gothamist.com/2008/08/21/repo...d_trade_ce.php

August 21, 2008

One of the lingering conspiracy theories surrounding the attacks on September 11, 2001 is that 7 World Trade Center, which was not hit by a plane, was deliberately destroyed (here's one example of a conspiracy website), because no other steel building has collapsed simply due to fire before. But now a report from the National Institute of Standards and Technology says that the fire is the culprit.

Lead investigator Shyam Sunder said, “Our study found that the fires in WTC 7, which were uncontrolled but otherwise similar to fires experienced in other tall buildings, caused an extraordinary event. Heating of floor beams and girders caused a critical support column to fail, initiating a fire-induced progressive collapse that brought the building down.” And referring to the fuel stored at 7 WTC, he added, "Video and photographic evidence combined with detailed computer simulations show that neither explosives nor fuel oil fires played a role in the collapse of WTC 7." The fires were started when debris from the World Trade Center towers fell onto the lower building.

The key factor contributing to the collapse is "thermal expansionof long-span floor systems at temperatures 'hundreds of degrees below those typically considered in current practice for fire resistance ratings.'" In other words, building owners, check your buildings. The report suggests that if a water main had not been broken due to the collapse at the Twin Towers, the sprinkler system at 7 WTC would have prevented the building's collapse.

You can read NIST's full report here (PDF). Former mayor Rudy Giuliani had placed his emergency command center at 7 WTC, in spite of NYPD recommendations against doing so.

http://www.newsweek.com/id/154494

It seems easier for me to critique their side of it now that it's down on paper. As Lorie, Patty said, etc... they wanted to get their words (lies) down on paper. They admit that what happened has NEVER happened before, and was an "extraordinary event." Extraordinary like the most defended airspace in the world being left completely undefended 34 minutes after the entire world knew America was "under attack?" Extraordinary like suspicious stock trades taking place indicating foreknowledge of 9/11? Extraordinary like appointing the worst possible person to the position of Executive Director of the 9/11 Commission? I am still not qualified to tell you who's right, and who's wrong... however, there was an important point made about how FEMA suggested there was a reaction in the metal, and how it coincides with what Jones found, and NIST didn't bother to look into that. Also, the guy the NYTimes talked to finished off with an insult about how we need psychologists. That's always an indication to me, that someone is lying about something. Personal insults are the last bastion of a failed argument. Does this mean now that every building owner with a similar construction is going to have to spend money to re-fit their buildings so they don't completely collapse from fire? My only other question is about previous fires that didn't collapse. They made a point to say that the falling of the towers destroyed the sprinkler systems, and WTC7 didn't have any. Did those previous buildings that stood after long periods of fire have sprinkler systems that worked? I dunno...

WTC 7 report: end of the line for 9/11 conspiracy theories?

http://www.bloggernews.net/117382

By Jefferson Flanders
Posted on August 23rd, 2008

The National Institute of Standards and Technology just-released final report on the collapse of World Trade Center 7 in 2001 following the 9/11 terrorist attack concludes that fire, not controlled demolition, was the cause of 47-story building’s destruction.

At an August 21st news conference, Shyam Sunder, the lead investigator for the federal building and fire safety investigation of the WTC disaster, explained: “Our take-home message today is that the reason for the collapse of World Trade Center 7 is no longer a mystery. WTC 7 collapsed because of fires fueled by office furnishings. It did not collapse from explosives or from diesel fuel fires. It collapsed because fires—similar to those experienced in other tall buildings—burned in the absence of water supply to operate the sprinklers, and burned beyond the ability of firefighters to control fires. It fell because thermal expansion, a phenomenon not considered in current building design practice, caused a fire-induced progressive collapse.”

Sunder directly addressed the question of whether controlled demolition had brought down WTC 7, a favorite theory of the “9/11 Truth Movement” and its celebrity hanger-ons, like Jesse Ventura, Charlie Sheen, and Rosie O’Donnell, noting that the investigative team had considered that possibility and rejected it. NIST concluded that “blast events inside the building did not occur” and “found no evidence supporting the existence of a blast event.” A NIST WTC 7 fact sheet summarized the case against controlled demolition:

In addition, no blast sounds were heard on the audio tracks of video recordings during the collapse of WTC 7 or reported by witnesses. According to calculations by the investigation team, the smallest blast capable of failing the building’s critical column would have resulted in a sound level of 130 decibels (dB) to 140 dB at a distance of at least half a mile, if unobstructed by surrounding buildings. This sound level is consistent with a gunshot blast, standing next to a jet plane engine, and more than 10 times louder than being in front of the speakers at a rock concert.

For the building to have been prepared for intentional demolition, walls and/or column enclosures and fireproofing would have to be removed and replaced without being detected. Preparing a column includes steps such as cutting sections with torches, which produces noxious and odorous fumes. Intentional demolition usually requires applying explosive charges to most, if not all, interior columns, not just one or a limited set of columns in a building.

The NIST WTC 7 team also found another popular 9/11 conspiracy theory, that thermite/thermate was used to sever columns was highly unlikely: “To apply thermite to a large steel column, approximately 0.13 lb of thermite would be needed to heat and melt each pound of steel. For a steel column that weighs approximately 1,000 lbs. per foot, at least 100 lbs. of thermite would need to be placed around the column, ignited, and remain in contact with the vertical steel surface as the thermite reaction took place. This is for one column … presumably, more than one column would have been prepared with thermite, if this approach were to be used.” NIST concluded that it was “unlikely that 100 lbs. of thermite, or more, could have been carried into WTC 7 and placed around columns without being detected, either prior to Sept. 11 or during that day.”

A blow to the 9/11 conspiracy theorists
The final NIST WTC 7 report represents a major blow to the promoters of 9/11 conspiracy theories. They began by claiming that the Twin Towers (WTC 1 and 2) had been felled by controlled demolition as part of a government “false flag operation.” Their argument had obvious flaws—it wasn’t hard to imagine that two large airliners loaded with jet fuel smashing into skyscrapers could inflict massive damage—and that was what the first NIST report concluded.

Their focus then turned to WTC 7, with many conspiracy theorists seizing on the fact that the building was not hit directly by the planes and “mysteriously” collapsed hours later. Again, they argued for controlled demolition, forcefully enough that NIST included explosions as a possible cause for the collapse in its investigation.

With the demolition theory for WTC 7 having been considered and rejected, the 9/11 conspiracy theorists are in a bind. The final NIST report offers what Sunder called a “simple and straightforward and elegant” explanation for the collapse of the building. The simplicity of the theory—that unchecked fires led to a chain of failures and then progressive collapse—and the extensive computer modeling of the hypothesis place it squarely in the best traditions of the scientific method.

The alternative theory advanced by the so-called 9/11 Truthers is far-fetched and requires a complete suspension of disbelief. Professional demolition experts have repeatedly explained that it takes weeks of work to prepare a building for a controlled demolition. And how could such a massive conspiracy, involving hundreds if not thousands of people, be kept silent? And what of the lack of any evidence of an explosion, as pointed out by the NIST team?

Despite the “on-the-record” scientific studies now explaining the WTC disaster, it’s unlikely that all members of the “9/11 Truth Movement” will go away quietly. Some make considerable amounts of money hawking 9/11 conspiracy DVDs and books. Others cling to the notion for deep-seated psychological reasons. Some are deluded. Yet the weight of the evidence is clear: the destruction of the World Trade Center buildings was directly caused by the actions of the 9/11 terrorists. To believe otherwise is to not only embrace an alternative theory, but to accept an alternative reality.

World Trade Centre building seven not destroyed by explosives, says US study
Smouldering debris from one of the fallen Twin Towers caused the skyscraper to collapse, investigation finds

http://www.guardian.co.uk/world/2008...eptember11.usa

8/24/2008

Smouldering debris from one of the fallen Twin Towers in New York City on September 11 2001 ignited flames at nearby World Trade Centre building seven, and the intense heat - not explosives - caused the skyscraper to collapse, according to a US report released yesterday.

The findings resulted from a three-year investigation by the National Institute of Standards and Technology, or NIST.

Though various experts have long believed fire played a role in loss of the building, NIST investigators claim it was the primary cause and "first known instance of fire causing the total collapse of a tall building".

"Obviously designers and engineers will be thinking of their buildings as they consider our report, and they'll take appropriate action," said Shyam Sunder, the lead investigator.

Guidelines for skyscraper construction in New York City and across the globe were revamped after the 2001 terror attacks. Since its destruction, building seven was replaced by owner Silverstein Properties.

Silverstein is also building office towers 2, 3 and 4 at Ground Zero.

"In rebuilding Seven World Trade Centre, we implemented structural and life-safety measures that set a new standard in modern skyscraper design - a standard that is being carried through to every tower we are building at the new World Trade Centre," said Dara McQuillan, spokesman for Silverstein.

Critics questioned why the investigation took so long, saying early on there were signs pointing to a fire-related collapse.

James Quintiere, professor of fire protection engineering at the University of Maryland, questioned how NIST was able to definitively rule out explosives, a longtime theory.

"They don't have the expertise on explosives, so I don't know how they came to that conclusion," said Quintiere, a frequent critic of the agency, where he formerly worked as chief of its fire science and engineering division.

Quintiere stressed, however, that he never believed explosives played a role. He said NIST wasted time employing outside experts to consider it.

After the World Trade Centre's North Tower fell at 10.29am, debris sparked fires at building seven, which was 370 feet (112.8 metres) south of the fallen tower.

It burned for several hours. Water supply lines for the building's automatic sprinkler system were cut off by the collapse of the Twin Towers, worsening fire conditions.

Heat from uncontrolled fires caused thermal expansion of steel beams, according to the report. When the beams expanded, they pushed supportive beams and damaged flooring surrounding columns.

Finally, a support column identified as No 79 buckled, triggering an "upward progression of floor system failure," according to the report.

"You have columns that's not supported ... and without something to hold them in place, they buckle," and the building collapses, Sunder said.

The scientific investigation considered other credible possibilities of what caused the building to fall, Sunder said, including explosives and a stored diesel fuel supply for backup generators. "We did not, even from the beginning, we did not have any evidence at all that demolition or charges or a blast were used to bring the building down," he said.

For future construction, the investigative team recommended support that can better withstand thermal expansion and a fail-safe for support beams.

The federal government allotted $16m to investigate the fall of the Twin Towers and building seven.

The Big Heat

http://www.counterpunch.org/garcia08222008.html

By MANUEL GARCIA, Jr.

Yesterday, the National Institute of Standards and Technology (NIST) issued its report on the collapse of World Trade Center Building 7 (WTC 7) on September 11, 2001. Collapse was caused by the rupturing of the building's metal framework due to the thermal expansion of its floor beams, which were heated by uncontrolled fires because the water main that supplied the building's fire suppression system had been cut by the collapse of WTC 1. NIST has posted a press release web page that includes a video presentation about, and two animations of their collapse model.

Nine excerpts from the NIST press release of August 21, 2008 follow, then my comments.

GAITHERSBURG, Md.—The fall of the 47-story World Trade Center building 7 (WTC 7) in New York City late in the afternoon of Sept. 11, 2001, was primarily due to fires, the Commerce Department’s National Institute of Standards and Technology (NIST) announced today following an extensive, three-year scientific and technical building and fire safety investigation. This was the first known instance of fire causing the total collapse of a tall building, the agency stated as it released for public comment its WTC investigation report and 13 recommendations for improving building and fire safety.

According to the report, a key factor leading to the eventual collapse of WTC 7 was thermal expansion of long-span floor systems at temperatures “hundreds of degrees below those typically considered in current practice for fire resistance ratings."

The investigators also reported that if the city water main had not been cut by the collapse of World Trade Center towers 1 and 2 (WTC 1 and WTC 2), operating sprinklers in WTC 7 would likely have prevented its collapse.

Determining the probable collapse sequence for WTC 7, NIST found that the impact of debris from the collapse of WTC 1 ignited fires on at least 10 floors of WTC 7, and the fires burned out of control on six lower floors. The heat from these uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors. Eventually, a girder on Floor 13 lost its connection to a critical interior column that provided support for the long floor spans on the east side of the building. The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the fifth floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of the critical column. This collapse of floors left the critical column unsupported over nine stories.

“When this critical column buckled due to lack of floor supports, it was the first domino in the chain,” Sunder explained. “What followed in rapid succession was a progression of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the most eastern side of the building. Then, progressing from east to west across WTC 7, all of the columns in the core of the building failed. Finally, the entire façade collapsed.”

The investigation team considered the possibility of other factors playing a role in the collapse of WTC 7, including the possible use of explosives, fires fed by the fuel supply tanks in and under the building, and damage from the falling debris of WTC 1.

The team said that the smallest blast event capable of crippling the critical column would have produced a “sound level of 130 to 140 decibels at a distance of half a mile,” yet no noise this loud was reported by witnesses or recorded on videos.

As for fuel fires, the team found that they could not have been sustained long enough, could not have generated sufficient heat to fail a critical column, and/or would have produced “large amounts of visible smoke” from Floors 5 and 6, which was not observed.

Finally, the report notes that “while debris impact from the collapse of WTC 1 initiated fires in WTC 7, the resulting structural damage had little effect in causing the collapse of WTC 7.”

I had thought the diesel fuel stored in the building would be needed to supply the necessary heat to weaken the metal framing near Column 80 through the first seven floors to the point of failure, and wrote this scenario in my article of November 2006.

Instead, NIST found that the beams of Floor 13 near Column 79 (one column north of Column 80, and closer to the building exterior) experienced the most heating, supplied entirely by the combustion of the furnishings, fixtures, paneling, and tenant materials on Floors 11 and 12, where the most intense burning had been observed. "Fires burned in sections of Floors 6 through 30 at different times, and they migrated along their floors independently, seeking new sources of fuel. From the street the fires on Floors 11 and 12 appeared most intense. Many fires in the area went unchecked because utility power for electrical pumps, and water pressure for fire engines had either diminished or been lost," I noted in 2006.

The beams of Floor 13 soaked in heat and expanded against their end joints, sagging under the increased compression along their lengths until the beam between perimeter Column 44 (on the east side of the north face) and interior Column 79 ruptured its joint to Column 79, initiating the collapse of the eastern end of Floor 13. The beams for eight floors below this point had been similarly weakened by fire, so the initial collapse sheared away nine floors of lateral supports to Column 79. Weakened by heat and now unable to transfer the load of the upper 34 floors laterally over a nine floor height, Column 79 buckled and this initiated the collapse of the entire eastern end of the building. See the NIST animation "Collapse Initiation -- Physics Based Model."

In rapid succession, the failure of Column 79 led to the loss of lateral supports to Column 80, then its subsequent failure and so on to Column 81, which three columns supported the eastern end of the building. Once the eastern end had fallen, collapse proceeded along the core of the building from east to west, and finally the exterior columns of the façade failed. See the NIST animation "Visualization Model of WTC Collapse."

NIST notes that any explosive capable of damaging Column 79 sufficiently to cause the observed collapse would be exceedingly loud for quite some distance (half mile), and no such blast was observed. Sound at 130 to 140 decibels is about as loud as humans can tolerate, beyond this power one is really encountering a blast wave, a jump in pressure that delivers sensible force. Examples of loud sounds and their effects include: a jet engine at 100 meters (110-140 dB), hearing damage due to short term exposure, for example front row at a rock concert (120 dB), threshold of pain (130 dB), a rifle being fired at 1 meter (140 dB).

NIST used to be called the NBS, the National Bureau of Standards. This was the agency within the Department of Commerce that was charged with keeping the standard clocks and rulers, against which all clocks and rulers were measured and calibrated. NBS never gave the impression of being a dynamic organization because it was expected to be unerringly reliable and trustworthy, and its published data on any topic or phenomenon was accepted as being the most accurate, complete, and exhaustively tested. The word "standards" is key to understanding the detail and pace of NIST work. A person without a grounding in science might not appreciate the value of this type of detailed, methodical work, and express impatience with the NIST "plodding" before arriving at conclusions on a topic of popular interest, like the phenomenology of the WTC building fires and collapses. The NIST scientists are clearly proud of their work on WTC 7, and it shows in the polish of the press release web site.

I am pleased that I got some of the story right (thermal expansion), and my error (oil fire) was a physically reasonable assumption for the time. I am consoled to the flaws of my analysis by the fact that the NIST effort to arrive at such accurate and detailed conclusions was a major effort of over three years. Learning is both humbling and interesting. The omniscient never learn because learning is the recognition of one's errors. I could rebel against learning by deciding my earlier ideas are an unappreciated revelation, which needs preservation despite the findings of later science, and I could devise elaborate arguments to protect my unrecognized ignorance. But defending ignorance is the essence of stupidity. A better approach would be to follow Socrates' dictum "The only thing I know is the fact that I am ignorant." Keep thinking, test your ideas, and don't become overly attached to them.

Linus Pauling (1901-1994) was a great scientist and peace activist who won two unshared Nobel prizes, for chemistry in 1954, and for peace in 1962. He made major contributions in quantum chemistry, and nearly unraveled the structure of the DNA molecule before Watson and Crick. In a recorded interview in his later life he was asked "how do you get so many good ideas?" His reply was "just keep having lots of ideas, and throw away the bad ones."

Manuel Garcia, Jr. is a retired physicist. E-mail = mango@idiom.com

World Trade Center 7 Report Puts 9/11 Conspiracy Theory to Rest
Conspiracy theorists have long claimed that explosives downed World Trade Center 7, north of the Twin Towers. The long-awaited report from the National Institute of Standards and Technology (NIST) conclusively rebuts those claims. Fire alone brought down the building, the report concludes, pointing to thermal expansion of key structural members as the culprit. The report also raises concerns that other large buildings might be more vulnerable to fire-induced structural failure than previously thought.

http://www.popularmechanics.com/scie...h/4278874.html

By Arianne Cohen
Published on: August 21, 2008

World Trade Center 7 stands amid the rubble of the recently collapsed Twin Towers. (Photograph by New York Office of Emergency Management)

The National Institute of Standards and Technology (NIST) has released its long-awaited report on the collapse of World Trade 7 following the attacks of Sept. 11, 2001. "Our take-home message today is that the reason for the collapse of World Trade Center 7 is no longer a mystery," NIST lead investigator Shyam Sunder told journalists at this morning's press conference in Gaithersburg, Md. "WTC 7 collapsed because of fires fueled by office furnishings. It did not collapse from explosives or from diesel fuel fires."

Conspiracy theorists have long pointed to the collapse of the 47-story structure as key evidence that the U.S. government orchestrated or abetted the 9/11 attacks. No planes struck the building, and the commonly available views of the exterior didn't show significant damage. Yet, at 5:20 pm, 7 hours after the collapse of the Twin Towers (WTC 1 and 2), WTC 7 rapidly fell in on itself. Since WTC 7 housed Secret Service and CIA offices, conspiracy theorists claimed that the building was destroyed in a controlled demolition in order to obliterate evidence of the U.S. government's complicity in the terrorist attacks. "It is impossible for a building to fall the way it fell without explosives being involved," stated actress and TV personality Rosie O'Donnell of ABC's The View in March 2007. "For the first time in history, steel was melted by fire. It is physically impossible," she said.

Today's report confirms that a fire was, indeed, the cause. "This is the first time that we are aware of, that a building taller than about 15 stories has collapsed primarily due to fires," Sunder told reporters at the press conference. "What we found was that uncontrolled building fires—similar to fires experienced in other tall buildings—caused an extraordinary event, the collapse of WTC7." The unprecedented nature of the event means that understanding the precise mechanism of the collapse is important not just to answer conspiracy theorists' questions, but to improve safety standards in the engineering of large buildings.

The final report describes how debris from the collapse of WTC 1 ignited fires on at least 10 floors of WTC 7 at the western half of the south face. Fires on Floors 7 through 9 and 11 through 13 burned out of control, because the water supply to the automatic sprinkler system had failed. The primary and backup water supply to the sprinkler systems for the lower floors relied on the city's water supply. Those water lines were damaged by the collapse of WTC 1 and 2. These uncontrolled fires in WTC 7 eventually spread to the northeast part of the building, where the collapse began.

After 7 hours of uncontrolled fires, a steel girder on Floor 13 lost its connection to one of the 81 columns supporting the building. Floor 13 collapsed, beginning a cascade of floor failures to Floor 5. Column 79, no longer supported by a girder, buckled, triggering a rapid succession of structural failures that moved from east to west. All 23 central columns, followed by the exterior columns, failed in what's known as a "progressive collapse"—that is, local damage that spreads from one structural element to another, eventually resulting in the collapse of the entire structure.

The report clarifies a number of widely debated issues concerning the collapse, particularly the role of the building's many diesel fuel tanks and the importance of structural damage from falling WTC 1 debris. Both of those factors have been cited by investigators as possibly contributing to the collapse; the 2006 Popular Mechanics book Debunking 9/11 Myths: Why Conspiracy Theories Can't Stand Up to the Facts mentions both hypotheses. However, the final NIST report downplays both scenarios, concluding that the diesel fuel stored in tanks (and intended to power backup generators) did not burn long enough or hot enough to account for structural failures. And, while debris damage to WTC 7's southern exterior was considerable (and initiated the destructive fires), the collapse originated in the northeast portion of the building. In fact, the report concludes: "Even without the structural damage, WTC 7 would have collapsed from fires."

The report determines that the actual culprit in the collapse was the combustion of ordinary building furnishings: "These uncontrolled fires had characteristics similar to those that have occurred previously in tall buildings." If the sprinkler system in WTC 7 had been working, it is likely that "the fires in WTC 7 would have been controlled and the collapse prevented." The report also suggests that current engineering standards for coping with fire-induced thermal expansion need to be re-examined, particularly for buildings like WTC 7 that have long, unsupported floor spans. A key factor in the collapse, NIST concluded, was the failure of structural "connections that were designed to resist gravity loads, but not thermally induced lateral loads." According to Sunder: "For the first time we have shown that fire can induce a progressive collapse."

Spurred by conspiracy theorists' questions, investigators did look specifically at the possibility that explosives were involved. "Hypothetical blast events did not play a role in the collapse of WTC 7," the report states, adding that investigators "found no evidence whose explanation required invocation of a blast event." Moreover, the smallest charge capable of initiating column failure "would have resulted in a sound level of 130 dB [decibels] to 140 dB at a distance of at least half a mile." Witnesses did not report hearing such a loud noise, nor is one audible on recordings of the collapse.

NIST will accept public comment on the final report until Sept. 15, 2008.

NIST's press release and other material on the report can be found here. Click here to download the full report in pdf form.

Our Opinion: Truth stranger than fiction
Some explanations hard for conspiracy theorists to accept

http://www.timesrecordnews.com/news/...anger-fiction/

Saturday, August 23, 2008

The thing about conspiracy theories is, no matter how much you prove them wrong, there’s always going to be some conspiracy theorist who thinks the latest findings are a conspiracy.

Whether it’s the grassy knoll, Area 51 or a lunar landing, some folks don’t want to accept the truth. And they’re rather insulted that the “truth” is presented as fact.

It never ends for some. It’s the thrill of the mystery that fuels the indefinite debate.

For others, though, solving a mystery aids in the healing.

The collapse of one of the World Trade Center buildings on Sept. 11, 2001, nurtured seven years’ worth of conspiracy theories, focusing on the implausibility of a steel-and-concrete structure inexplicably falling down.

Conspiracy theories involving the 9-11 attacks are a cottage industry -- Did the government know? Did the government bring down buildings 1 and 2? Those buildings collapsing like a child’s toy tower seemed impossible to us, even as we watched it happen. Something else, something extraordinary must have caused their demise -- as if two fully fueled jets crashing into their sides weren’t enough.

Much contemplation went into solving the collapse of Building 7, mainly because skeptics couldn’t believe that fire and debris alone could have brought down the trapezoid structure that sat north of the World Trade Center towers.

And the fact that the building collapsed some seven hours after the first two fell, according to the Associated Press, baffled the skeptics.

A 77-page federal report released this week aims to solve the mystery and end the speculation once and for all. Federal investigators said that the collapse resulted from fire from burning debris falling from the towers, exacerbated by a sprinkler system deemed inoperable after the enormous collapses.

“The public should really recognize the science is really behind what we have said,” said an investigator. “The obvious stares you in the face.”

Scientists with the National Institute of Standards and Technology, the AP reported, determined that collapse of WTC 7 was actually the first time in the world a fire caused the total failure of a skyscraper.

“Hopefully this thorough report puts to rest the various 9/11 conspiracy theories, which dishonor the men and women who lost their lives on that terrible day,” said Dara McQuillen, a spokesperson for the leaser, Larry Silverstein.

The total failure of a skyscraper is something hard to accept. It’s much easier to assume conspiracies. But perhaps it’s time to let this one go.

Twin towers mystery resolved, fire brought down WTC7

http://www.thetechherald.com/article...ught-down-WTC7

8/24/2008

A long-standing conspiracy theory concerning the destruction of the 47-story World Trade Centre building 7, located to the north of the Twin Towers, has been debunked.

Federal investigators with the National Institute of Standards and Technology (NIST) handed down the findings of a three-year investigation which said fire from falling debris caused the collapse of the building making it the first time a fire had caused the total failure of a modern skyscraper.

"The reason for the collapse of World Trade Center 7 is no longer a mystery," said Dr. Shyam Sunder, the lead investigator on the NIST team. "It did not collapse from explosives or fuel oil fires."

Skeptics have long believed that fire and debris alone should not have caused the collapse of such a strong building and have hinted at a timed explosion as being the cause of the collapse. The building was not hit at any stage by the hijacked aircraft.

However the report dismissed this suggestion saying other factors brought the building down.

"Heating of floor beams and girders caused a critical support column to fail," said Sunder. "Video and photographic evidence combined with detailed computer simulations show that neither explosives nor fuel oils played a role in the collapse that brought the building down."

However, the report is unlikely to satisfy conspiracy theorists, with the New York Times quoting a survey claiming 1-in-7 Americans believes the attack on the World Trade Centre was an inside job.

"Seven World Trade Centre is one of the key points of evidence, one of the smoking guns," said Richard Gage, a California architect and leader of a group called Architects and Engineers for 9/11 Truth, to the newspaper. "There have been much hotter, longer lasting and larger fires in skyscrapers that have not fallen down."

For a demonstration video of why the building fell, see the NIST Web site by clicking here.

Truthers, over and out
NIST report credibly explains fall of WTC 7

http://www.rockymountainnews.com/new...-over-and-out/

Rocky Mountain News
Tuesday, August 26, 2008

'What about World Trade Center 7?"

That question has always been the trump card for the " 9/11 Truthers" - conspiracy buffs who have peddled the mind-boggling theory that the 2001 attacks on the World Trade Center and the Pentagon were an inside job, plotted and even executed by the federal government as a way to justify the war on terror.

The answer to the Truthers' question - how that 47-story building could collapse into a fiery heap when it wasn't hit by a plane - was provided definitively in a report issued last week by the National Institute of Standards and Technology. The NIST report is so exhaustive that it should put to rest wild notions, including one suggesting that bombs were planted in the structure and detonated to erase key evidence about the plot.

That said, we're not about to believe for a New York minute that the loopier 9/11 Truthers will accept those findings.

The more level-headed among us have little trouble accepting the uncomplicated (and hence credible) explanation that the 9/11 attacks were devised by Osama bin Laden and fellow jihadists to demonstrate the vulnerability of the "decadent" West to terror attacks.

Not so fast, the Truthers have insisted. What about WTC 7? Why would that structure collapse seven hours after the Twin Towers fell unless it was brought down by a controlled detonation?

The explanation, quite simply: uncontrolled fires, which burned to an intensity hot enough and long enough to compromise the steel girders holding up the structure.

The 66-page report, available at wtc.nist.gov, resulting from a three-year technical investigation, including simulations of the event, noted that the debris from World Trade Center Building 1 ignited fires on at least 10 lower floors of WTC 7. Fires on floors 7 through 9 and 11 through 13 burned for at least seven hours.

They raged unabated because the building's primary and secondary water source for sprinklers on the bottom 20 floors originated from city water mains - and those water lines were damaged by the impact of the Twin Towers collapse.

Without any way to feed water to sprinklers, fires from office furniture and paper rose to temperatures that caused the steel girders to expand. Temperatures weren't hot enough to melt the girders, but without any relief, over time the expansion compromised their integrity. A girder on the 13th floor lost contact with one of the 81 columns supporting the building. That floor collapsed, taking the eight floors below it.

Then one interior column buckled. When it failed, the 23 other central columns supporting the building soon followed, and the structure could no longer support itself.

"This is the first time that we are aware of that a building taller than about 15 stories has collapsed primarily due to fires," said NIST lead investigator Shyam Sunder at a Thursday press conference.

This unprecedented event has highlighted structural vulnerabilities in other skyscrapers. And the report offered 13 recommendations for ways to make those buildings safer - some as minor as redesigning work spaces to prevent fires from spreading from one cubicle to another.

The NIST report might not placate the more unhinged Truthers. But it should prod building owners to take small steps that prevent future tragedies.