Reply #20: The NOVA program may be available on DVD in a library near you,

[petgoat]

AZCat. When you watch it keep in mind that the animations of the
"zipper" truss failure are extremely dishonest because they omit the
lateral trusses that join all the floor trusses together. Note also how
the graphics minimize the robust nature of the core structure.

Remember while watching it that while the "zipper" theory supposes that
the trusses are anchored to the perimeter columns by very weak "clips",
the NIST hypothesis is that the trusses were so strongly anchored that
sagging floors were able to buckle the perimeter columns.

Take special note of the testimony of Brian Clarke. He walked down
from the South Tower right through the fire zone. He said he saw some
flames, but no blazing inferno. He stopped around the 30th floor to
make some phone calls and then walked away down the street. When his
friend said the tower might fall, Clarke said "No way. Those are
steel-framed structures."