https://www.ae911truth.org/evidence/high-temperature-thermitic-reactions 'High-Temperature Thermitic Reactions | Twin Towers Despite the illegal destruction of most of the structural steel and other debris in the months after 9/11, a sizeable body of forensic evidence has been developed over the years by government investigators and independent researchers. Much of the available evidence indicates the occurrence of high-temperature thermitic reactions before, during, and after the destruction of the towers. NFPA 921: Guide for Fire and Explosion Investigations, which serves as the national guide for fire and explosion investigations in the United States, advises that “All available fuel sources should be considered and eliminated until one fuel can be identified as meeting all the physical damage criteria as well as any other significant data.” [Emphasis added.] On the potential use of exotic accelerants, including thermite, NFPA 921 further advises: “Indicators of exotic accelerants include...melted steel or concrete.” The National Institute of Standards and Technology (NIST), however, did not follow NFPA 921 in its investigation of the World Trade Center destruction. Instead, it handled the evidence of high-temperature thermitic reactions in much the same way it handled the evidence regarding the structural behavior of the buildings: either denying it, ignoring it, or providing speculative explanations not based upon scientific analysis.' ...