What the BYU professor say's is also in a FEMA study.
http://911research.wtc7.net/wtc/evidence/metallurgy/index.html
http://911research.wtc7.net/wtc/official/fema.html
Firefighter Audiotape
Reports from Firefighters at the Impact Zone Inside the South Tower
The New York Times revealed the existence of a 78-minute audiotape of radio transmissions of the New York Fire Department (FDNY), which proves that at least two firefighters reached the 78th floor sky lobby of the South Tower.
1
Chief Oreo Palmer radioed from the 78th floor of the South Tower.
For over a year the Port Authority of New York and New Jersey with the blessing of the U.S. Justice Department refused to release the contents of the tape. In August of 2002, excerpts from Chief Palmer and others were released. In early November of 2002, the entire tape was released to the
New York Times, then to other unspecified "news outlets" (according to the Associated Press).
11[/color]12
Seven minutes before the collapse, battalion chief Palmer is heard to say "Ladder 15, we've got two isolated pockets of fire. We should be able to knock it down with two lines." The widow of Chief Palmer was allowed to hear the tape before excerpts were released by the Times. She said:
I didn't hear fear, I didn't hear panic. When the tape is made public to the world, people will hear that they all went about their jobs without fear, and selflessly.
Palmer called for a pair of engine companies to fight the fires. The fact that veteran firefighters showed no sign of fear or panic, and had a coherent plan for fighting the fire, contradicts the
official explanation of the collapses that the fires were so hot and extensive that they weakened the steel structure.
http://www.thememoryhole.org/911/firefighter-tape-excerpts.htm