The fireproofing was scraped off the steel by the crash, so the beams melted. - Edit 1
Before modification by Aeryn at 21/09/2011 07:37:26 PM
It was the fire more than anything that did the damage, and that the planes bent the beams & scraped off the fireproofing. Then once one floor collapsed, the one below couldn't hold the weight, and down it went.
(I read a heartbreaking interview with the structural engineer who designed WTC. He got some praise that the buildings stood for as long as they did; that was unexpected given the tremendous strains they were subject to, and saved thousands of lives.)
(I read a heartbreaking interview with the structural engineer who designed WTC. He got some praise that the buildings stood for as long as they did; that was unexpected given the tremendous strains they were subject to, and saved thousands of lives.)