In the June, 2006 paper Mechanics
of Progressive Collapse: Learning from World Trade Center and
Building Demolitions, by Zdenek P. Bazant and Mathieu Verdure, the
authors make the following stunning statement:

The destruction of the World Trade Center (WTC) on
9/11/01 was not only the biggest mass murder in the U.S. history
but also a big surprise for the structural engineering profession,
perhaps the biggest since the collapse of Tacoma Bridge in
1940. No experienced structural engineer watching the attack
expected the WTC towers to collapse. No skyscraper has ever
before collapsed due to fire. The fact that the WTC towers
did, beckons deep examination.

This statement defies all credulity. Mind you, we are
discussing three steel-framed skyscraper collapses due to
fire, at the same site, and on the same day. If we were to accept
the specious thesis that fire did indeed cause these buildings to
collapse, then we would be forced to believe that hudreds of
thousands of people work and live in potential death-traps whose
safety is both extremely suspect, and almost completely
unassessed.

Leaving that absurdity aside let us ponder an equally
outlandish proposition. No experienced structural engineer
expected the towers would collapse under those conditions, but the NYC OEM
issued a WTC collapse warning. How did they know?

File No. 9110161

WORLD TRADE CENTER TASK FORCE
INTERVIEW

EMT RICHARD ZARRILLO

Interview Date: October 25, 2001

...Again, times are a little fuzzy initially for me. A few
minutes later, John came to me and said you need to go find
Chief Ganci and relay the following message: that the buildings
have been compromised, we need to evacuate, they're going to
collapse. I said okay. I went down Vesey Street towards
West.

Q. You were by yourself?

A. I was by myself, me and my helmet and my radio. I got to
the corner of Vesey and West. I found some EMS vehicles. I think
I saw Chief Gombo there. I'm not really sure. I mentioned to the
EMS people there, again, not knowing who they were, I said you
need to get away from here, the building might collapse, we need
to leave this spot.

As I was walking towards the Fire command post, I found
Steve Mosiello. I said, Steve, where's the boss? I have to give
him a message. He said, well, what's the message? I said the
buildings are going to collapse; we need to evac everybody
out. With a very confused look he said who told you that? I
said I was just with John at OEM. OEM says the buildings are
going to collapse; we need to get out.

He escorted me over to Chief Ganci. He said, hey, Pete, we
got a message that the buildings are going to collapse. His
reply was who the fuck told you that? Then Steve brought me in
and with Chief Ganci, Commissioner Feehan, Steve, I believe
Chief Turi was initially there, I said, listen, I was just at
OEM. The message I was given was that the buildings are going to
collapse; we need to get our people out. At that moment, this
thunderous, rolling roar came down and that's when the building
came down, the first tower came down.