In this short documentary-style video, I outline the mathematics and science of WTC7 as it relates to its uniform 6.5 second collapse at 5:20 pm on the evening of September 11th. I also briefly touch upon the government analyses conducted by FEMA and NIST, and I compare the collapse to known controlled demolitions and similar steel structures with fire and/or structural damage. Additional info that the viewer may find applicable is that more than half of the diesel fuel was recovered by the two largest underground storage tanks post-collapse (documented by FEMA), and that fires on the north, west, and east sides of the building did not appear to be out of control. In the intro to the vid, the BBC field reporter mysteriously digitizes out of the conversation minutes before WTC7's collapse, after having prematurely reported its collapse 20 minutes before it occured (with the building standing behind the field reporter in plain sight). Also interesting to note, if the hypothesis of NIST is true, then controlled demolition crews only have to weaken one core column in a skyscraper to perfectly implode it.

At 5:20 p.m. on the evening of September 11th, 2001, the Salomon Brothers Building, also known as 7 World Trade Center (WTC7), the northernmost building on the World Trade Center complex, uniformly collapsed in 6.5 seconds. It produced a rubble pile with a radius similar its original dimensions and approximately seven stories tall [1].

There are two theories regarding how did WTC 7 collapse, part of September 11 attacks that hit the United Sates six years ago and changed the political map of the entire world and the U.S. foreign policies in the Middle East.

Some analysts attributed the collapse to structural failure due to prior debris impact and ongoing fire damage. The other theory suggests the building collapsed as a result of controlled demolition- many support the second theory given the lack of precedent of total collapses of steel framed structures during fires.

But the controversy over the collapse of Building 7 that the Bush administration has so far failed to explain is being brought up again in 2007 with more shocking revelations.

Websites and blog pages began in recent weeks circulating commentaries about the shocking BBC News reporting of the collapse of WTC7 before the incident actually took place.

''We built in enough redundancy to allow entire portions of floors to be removed without affecting the building's structural integrity, on the assumption that someone might need double-height floors,'' said Larry Silverstein, president of the company. ''Sure enough, Salomon had that need. Source: http://query.nytimes.com/gst/fullpage.html?res=950DEFDD113BF93AA25751C0A96F948260&sec=&spon=&pagewanted=1

The comment and NY Times article above completely brings into question the fire/gravity reason for the collapse of WTC 7.