A word in your ear.
When steel heats up, does it retain its original stiffness and load-bearing capacity?
"Heat treating," it gets stronger!!
I'm headed off for more booze, then sleep. Long day and I'm getting slap happy.
Besides all that: The buildings collapsed as fast as a FREEFALLING rock. Given the government scenario, that should have been impossible.
Steel burns at 2400 degrees, it melts at about 1250 degrees. If it is exposed to 900 degree heat for about 40 minutes it loses about 50% of its strength and begins to experience plastic deformation. I do not know if Experiences Brash failure under a Static load, but under active loading it will.
Hijackers seen again in SA; If you get on a plane in Boston take off, and that plane flies into a building, but the people are seen in SA then they would have to get off somewhere.. where did the plane stop to allow them to get off? IT would be noted somewhere. It wasn't. The idea they were seen again in SA is dubious.