from the way wtc 1&2 fell.. i see no "collapse",
"the enormous force delivered in the form of gravity pulling on the upper floors, which led to the chain reaction collapse."
from what i see.. the top exploded and the rest turned to dust, instantly.
watch it and see.
there are endless...
if it was so hot in there then how come people were clearly seen in the entrance hole?
'Like wtc 7
ever made a campfire?
more smoke equals less heat, really hot flames produce very little smoke.
the smoke that came from wtc 1&2 was black.
say the steel did weaken...