Stephen C. Webster
Rawstory.com
Published: Thursday August 21, 2008

According to a federal agency report released Thursday, a "new phenomenon" known as thermal expansion was directly responsible for the mysterious collapse of World Trade Center 7 on Sept. 11, 2001.

This study, posed by the National Institute of Standards and Technology -- a federal scientific agency which promotes technical industrial standards -- marks the first 'official' government theory on the collapse.

The building's demise occurred some seven hours after the twin towers collapsed on Sept. 11, 2001, and has been the source of numerous conspiracy theories key to the "9/11 Truth" movement, most of which argue that the symmetrical, seven-second collapse was brought about by a controlled demolition.

Dr. Shyam Sunder, director of Institute's building and fire research laboratory, oversaw the government's three-year research efforts. The report aims to disprove the controlled demolition argument.

However, Richard Gage, founder of Architects & Engineers for 9/11 Truth and a member of the American Institute of Architects, doesn't believe a word of the theory.

His group, which has swelled to over 400 architectural and engineering professionals, immediately responded to the Institute's claim in a press conference.

"Tons of [molten metal] was found 21 days after the attack," said Gage in an interview with a Vancouver, Canada television station. "Steel doesn't begin to melt until 2,700 degrees, which is much hotter than what these fires could have caused."

"There are holes in this story that you can drive a truck through," Gage added during the press conference. His group asserts that thermite, a steel cutting agent, was used to bring the building down.

Dr. Sunder disagreed.

"We conducted the study without bias, without interference from anyone," said Dr. Sunder. "We have only one single-minded goal in this effort."

While the Institute said it considered the possibility of a controlled demolition taking place at WTC 7, the notion was dismissed due to the absence of any recordings of an explosion sound.

Thermite, however, does not make an explosion sound. And while this was raised to Dr. Sunder in the media's Q&A session, he dismissed it as impossible.

"FEMA found it," said Gage. "Dr. Steven Jones found it, in the dust that landed in the entire area of lower Manhattan. And he finds it in the chunks of previously molten metal [from the towers]."

Specifically, in Appendix C of its World Trade Center Building Performance Study, FEMA claimed:

Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure. A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel... The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified.

Yet, no study of the mysterious sulfur or melted steel was included in the NIST report.

After New York City officials cut off the water main to the tower Sept. 11, 2001, the building's sprinkler system was unable to function, Dr. Sunder said. This allowed fires across 10 floors to burn uncontrolled for nearly seven hours.

The Institute asserts that due to the lack of water supply, an “extraordinary event” occurred, and for the first time ever, steel expanding due to heat from the flames caused columns to separate from structural concrete. Column 79 was the first to fail, according to the report, which brought about a quick succession of failures in adjoining columns.

"Thermal expansion of long-span floor systems" was a critical element in the collapse, said Dr. Sunder. The "kink" seen in the building's penthouse portion in video of the collapse was in-line with the columns which failed first.

"If water had been available, it is likely that sprinklers would have operated and the building may still be here today," he said.

"It looks like they want to wrap-up this investigation and blame [the collapse] on normal office fires," said Gage during counter-conference.

WTC 7's structural system is in "widespread use" in other buildings, he added, insisting that such effects may also be present elsewhere. The Institute's report also includes recommendations for the strengthening of building codes to avoid future thermal expansion-driven collapses.

The collapse of WTC 7 is "no longer a mystery," Dr. Sunder claimed.

The Institute's full report is available at wtc.nist.gov.

Further details from the Architects & Engineers for 9/11 Truth press conference are forthcoming.