Reply #10: Watch the WTC 1 collapse

[longship]

If you watch the WTC 1 collapse, it begins by the top several floors, above the impact zone, tilting over towards one side. That's when the floors just below the impact zone begin to give way. From the film it is apparent that the floor sections in that zone collapsed on one side. The additional stress on the floors below that made them collapse, too, and the catastrophe was on it's way. The top section during that time stopped it's lean and proceeds to fall straight down with the rest of the building as the floors pancaked on one another. The end effect was that the building collapsed into its own footprint (or more or less so since the entire area for a block or two had significant flying debris from the collapse.) The whole process begins slowly but picks up speed very quickly as the whole building's integrity fails catastropically.

The damaged area to the corner of WTC 7 in the photo is about a third of the way up the building. I suspect that a similar thing happened in WTC 7 as happened in WTC 1. I have not seen a clear shot of WTC 7 collapse from that viewpoint and I suspect such a film does not exist given the hazards in that area after the two big towers collapsed. The shot in the pic was taken by a police coptor.

It's possible that the WTC 7 collapse took debris more towards that damaged corner than away from it, but since we have no film to show that, one would have to have looked at the debris field after the collapse. I'm sure that they did that. But there's no way to answer your question without that knowledge. The one sequence of the WTC 7 collapse I've seen was from the opposite viewpoint. I sure looks like it collapses mostly straight down. That's what the physics says should happen.