[Robert A Cook PE]

The floor joists did NOT melt, but merely had to "slightly soften" (an orange glow indicating 800-110 degrees) in metal means it has NO strength, and bends under very little pressure) so that the walls fell in on themselves.

If I heat the center of an 1/2 sq bar to a yellow heat with my torch, I can bend and twist the bar with my thumb and one finger's pressure at the other end.

[gleeaikin]

Yes, I agree. What the diagrams showed was a sagging of the floor joists to the point that they pulled the attached wall columns inward about 4 or 5 feet at which point they buckled inward.

Regarding the planes not hitting the towers, where are the hundred plus missing airplane passengers and crew. BOY, some coverup that must be, IMAGINE, noone has even disclosed it. Come on coverup conspirator buffs, use some imagination.