[George W. Bush]

ABC news has some architectural experts who are in agreement that the fires in this building (1500 degrees F) caused the steel to weaken and it then became unable to support the weight once the tensile strength of the steel was depleted. So, the structure was sound enough to withstand the impact. It was just that the loadbearing steel was weakened by the fire. When the top floors fell, it was too much stress for the lower structure and the whole thing collapsed straight down without tipping. Straight down in a pile.

I think within three days, we're all going to be sick of structural analysis.

[Looking for Diogenes]

Speaking of heat damage, I have read reports that the airplanes' "Black Boxes" are not likely to have survived the fires.

[Fury]

ABC news has some architectural experts who are in agreement that the fires in this building (1500 degrees F) caused the steel to weaken and it then became unable to support the weight once the tensile strength of the steel was depleted. So, the structure was sound enough to withstand the impact. It was just that the loadbearing steel was weakened by the fire. When the top floors fell, it was too much stress for the lower structure and the whole thing collapsed straight down without tipping. Straight down in a pile. I hope the CVR and FDR boxes from these aircraft somehow were thrown clear and survived. I would expect that they could yield some valuable data, perhaps some final statement from those involved. However, if they were subjected to those temps, they are gone...