Reply #23: Sorry, but I'll have to take the word of the Senior Communications Officer of NIST on this one...

[Ghost in the Machine]

He says the *only* steel they were able to positively identify was from the Twin Towers. I'm guessing because of the 'tube in a tube' design?

"NIST sought to positively identify the origin of all steel used in its investigation of the World Trade Center disaster. This was accomplished either through identifying markings (stampings) or by geometry of the recovered steel. Of the seven buildings in the WTC complex, only the towers (WTC 1 and WTC 2) had identifying markings, or shapes of columns or beams sufficient to unambiguously identify the original building. It was not possible to unambiguously distinguish the steel from the hotel (WTC 3), the three similar nine story buildings (WTC 4 through WTC 6) and the 47-story WTC 7."

Here's his contact information if you think he's wrong.. or if you know something he doesn't:

Michael E. Newman
Senior Communications Officer
Public Affairs Office
National Institute of Standards and Technology
100 Bureau Drive, Stop 1070
Gaithersburg, MD 20899-1070

Phone: [phone]
FAX: [phone]
E-mail: [e-mail]

NIST info at http://www.nist.gov
NIST news and Tech Beat newsletter at http://www.nist.gov/news
WTC investigation info at http://wtc/nist.gov