Extremely high temperatures were evident before and during the destruction of the World Trade Center Twin Towers and at Ground Zero. Seven minutes before the destruction of the South Tower, a flow of molten metal appeared, accompanied by several smaller flows, as documented by the National Institute of Standards and Technology (NIST). The material’s glowing color showed that its temperature was close to “white hot” at the very beginning of the flow and “yellow-orange” further down. Iron-rich spheres in the WTC dust are additional proof of temperatures above the melting point of iron. Pyroclastic-like, rapidly expanding dust clouds after the destruction of the Towers can also be explained only by the expansion of hot gases.
The high-temperature phenomena at Ground Zero are documented by various sources:
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| An excavating machine at Ground Zero lifts debris dripping with molten metal |
Bechtel engineers, responsible for safety at Ground Zero, wrote in the Journal of the American Society of Safety Engineers: “The debris pile at Ground Zero was always tremendously hot. Thermal measurements taken by helicopter each day showed underground temperatures ranging from 400ºF to more than 2,800ºF.”
The fact that high-temperature phenomena were an important issue at Ground Zero is underscored by the large number of thermal images acquired: images by SPOT, MTI,AVIRIS/NASA, "Twin Otter"/U.S. Army, and at least 25 images by EarthData, taken between Sept. 16 and Oct. 25. In addition, temperature measurements by helicopter were taken each day, and the firefighters used onsite sensors too.

















