National Institute of Standards and Technology released a progress report in June 2004, outlining its working hypothesis, which was that a local failure in a critical column, caused by damage from either fire or falling debris from the collapses of the two towers, progressed first vertically and then horizontally to result in "a disproportionate collapse of the entire structure". In a magazine interview in March 2006, Dr S. Shyam Sunder, (PICTURED BELOW) NIST's lead WTC disaster investigator, said, of 7 World Trade Center, "We are studying the horizontal movement east to west, internal to the structure, on the fifth to seventh floors”; he added "But truthfully, I don’t really know. We’ve had trouble getting a handle on Building No. 7".
Despite FEMA's preliminary finding that fire caused the collapse, some believe the building seven collapse was the result of a controlled-demolition. Because this would imply that a vast number of involved people had, and continue to have, almost no regard for human life whatsoever, (we don't know anyone like that now, do we?) such claims are widely disputed. When asked about controlled demolition theories, Dr. Sunder said, "We consulted 80 public-sector experts and 125 private-sector experts. It is a Who’s Who of experts. People look for other solutions. As scientists, we can’t worry about that. Facts are facts." In answer to the question of whether "a controlled-demolition hypothesis is being considered to explain the collapse", NIST said that, "while NIST has found no evidence of a blast or controlled demolition event, it would like to determine the magnitude of hypothetical blast scenarios that could have led to the structural failure of one or more critical elements."
The New 7WTC
NIST anticipates the release of a draft report of 7 WTC by the end of 2007. What could possibly be taking so long? The replacement building has already been built!
Here is a good summary of the problems with the report, or lack thereof.