Your right, regarding my assumption that the building is hiding a flash, but it is perfectly feasible and possible that a small explosion would not be visible at that angle. Saying you don't see a flash and therefore it wasn't an explosion is incorrect.
The lack of a visible flash does not rule out the possibility of an explosion.
Regarding the other burning materials such as tables, chairs, etc. The official story states the intense heat from the burning jet fuel weakened the steel supports and caused the collapse. If you are saying other materials caused the intense heat to weaken the steel, I'd have to disagree with you. Never has fire brought down a steel framed building. As I said earlier, one of the towers suffered a fire in the 70's and didn't come collapsing down.
Additionally, only two small fires were reported in one of the buildings by the firefighters that had climbed all the way up to the impact location, therefore the theory of intense searing heat weakening the steel supports is simply hogwash.
Here's an image:
This is the impact location on one of the towers. There are two people visible, one is laying down and another is leaning over. This is actually a blow up of a bigger picture which shows at least one more person looking out.
This picture tells us a couple of things, first of all, the fire was not hot, at least in this location. A fire hot enough to weaken steel would have incinerated these people. As you can see, these people look fine, their clothes are fine, their hair isn't singed. Furthermore, a large hot fire will require significant oxygen. If such a fire existed, the air would be funneling in through this hole to feed the fire.
Secondly, these people are leaning out the hole 90 stories up. If there had been any indication of structural damage from the plane crash, there is no way they would venture out this far. Picture a creaking, wobbly building, ready to collapse. Would you venture out to this point 90 stories up?
By the way, a lot of what I'm saying is assumptions and theory, but that's the point of this. Taking a look at the evidence and drawing conclusions based on the evidence and common sense.