From: moroney@world.std.spaamtrap.com (Michael Moroney)
Newsgroups: sci.geo.geology sci.physics sci.geo.petroleum sci.engr.mining aus.invest aus.science uk.finance
Subject: Re: THE DEATH TOLL SHOULD HAVE BEEN LOWER
Date: Fri, 12 Sep 2003 19:42:41 +0000 (UTC)

Fool.  The World Trade Center's structural support was of _steel_, not 
concrete.  The only concrete used was in the foundations and the floors.  
Even the floors weren't self-supporting, they sat on steel trusses.  The 
buildings collapsed because the fires caused the steel on the impact 
floors to soften and weaken in the heat so finally one or more floors 
simply collapsed.  Then each wall below it suddenly not only had to 
support the static weight of the floors above it (which they were designed 
to do) but the dynamic force of entire building above it falling at least 
1 storey. Kind of like an individual in good shape can hold a similar 
person off the ground, but let's see him _catch_ the second person jumping 
from 10 feet onto him without collapsing himself.

Note that the floors did nothing to support the building above it.
The steel floor beams did connect the core with the outer walls, 
stiffening them.

If the concrete survived as chunks or relatively intact, where would we 
be?  Just as many dead, except perhaps more bodies could have been
recovered, squashed flat between concrete layers of floors.