moondog - your post contains so many errors it's obvious you have neither the qualifications to comment on the properties of materials nor have you bothered to read any of the authoritative writings of professional structural engineers who consider both the FEMA and NIST accounts of performance failure absurd.....
by the way, both FEMA and NIST, the official 911 "investigators" eventually were forced by both logic and pressure from qualified groups (not conspiracy theorists) to make the statement that they had no explanation for the total collapse of any of the three WTC towers - they abandoned their original hasty and erroneous 'pancake' theory and replaced it with.... nothing....
if you demonstrated any impartial perspective of the 911 events I would be happy to engage you in a reasoned debate, but it's apparent that you have closed your mind to any alternative account of 911 - I'm happy to leave you there.....
you see, I don't know what happened on 911, neither does anyone else - what reasonable, highly qualified engineers, pilots, firefighters, scholars are attempting to do is to reopen the 911 investigation to find out what really happened that day
