Building 7 Implosion: The Smoking Gun of 9/11 Written by Richard Gage, AIA, Gregg Roberts, and David Chandler Tuesday, 24 August 2010

Seven hours after the destruction of the World Trade Center Twin Towers, a third high-rise building collapsed. The characteristic signs of controlled demolition were abundant.

Neither jet fuel nor office fires can reach anywhere close to steel’s melting point, much less its evaporation point, even if those critical temperatures had been lowered by the presence of free sulfur. So what could have caused this “high temperature corrosion attack?”

Thermite is a mixture of powdered iron oxide and elemental aluminum which, when ignited, reacts violently at 4,000-4,500° Fahrenheit (F) – well above the melting point of steel or iron, about 2,800° F, producing aluminum oxide and molten iron. When free sulfur is added to the mixture, the iron melts at a lower temperature. Thermite with sulfur added is called thermate. Structural steel in contact with ignited thermate also melts at a lower temperature. Contrary to what NIST and others have claimed, the sulfur could not have come from gypsum wallboard, where it is an inert, chemically “locked” ingredient.

The United States Geological Survey (USGS) used NASA thermal imaging of the WTC rubble pile surface to document hot spots with extreme temperatures of almost 1,400° F. These temperatures are hotter than most office fires produce, and there were no fires on the surface of the WTC 7 pile following the collapses. The detected surface temperatures indicate much higher temperatures deeper within the pile. These extreme temperatures persisted for several weeks, despite the continuous spraying of millions of gallons of water onto the debris pile – so much water that one worker described the result as “a giant lake.” Thermite contains its own source of oxygen and burns just as well under water.

http://www1.ae911truth.org/home/344-building-7-implosion-the-smoking-gun-of-911.html