"Brian Whatcott" wrote in message
...
On Sat, 26 May 2007 03:22:11 +0000, Larry wrote:

Grade School Physics Factoid:
A building cannot freefall into its own footprint without
skilled demolition.

Civil Engineering Graduate School Fact:

For a tall building to collapse on its footprint, the central support
column should be gravity load bearing and the edge columns should
provide the wind resistance structure . Like, oh, the World Trade
towers.

Gravity overload pulls out the center column fixings, while the edge
columns provide precision collapse guidance.

How 'bout that!

Brian Whatcott Altus OK


Not for nothing, but the central support columnS (multiple) were not even
touched by the planes.