What caused the unusual collapses of 3 buildings on 9/11, include the famous Twin Tower? An article I wrote a few day after 9/11 and tried to publish as a newspaper editorial stated explosions did it, and the has been since proposed many thousands of times. Evidence for high temperatures and explosive use was posed with the potential involvement of thermite by Jones in 2006, and evidence for very high temperatures in the WTC dust, much higher than fire can produce was published by a group of us in 2008.[2,3] A strong suggestion of the use of nano-thermites was proposed shortly afterward.
Thermite is a mixture of aluminum and iron oxide that when heated to high temperatures (above 900° C) undergoes a very strong exothermic (heat-releasing) reaction to produce a very incendiary device. Nano-thermites are new level of finely mixed crystals of these reactants that have a lower setoff temperature and more explosive reaction. The extensive evidence found for nano-thermites prevalent in the WTC dust for all 3 collapsed buildings was published in early 2009.[5,6]
What the internation group of scientists, headed by Danish chemist Neils Harrit, found was an active thermitic material in the form of microscopic red-gray chips (see Figure 1) detected using a scanning electron microscope (SEM). X-ray energy dispersion graphs were used to identiy the individual elements. The gray chips were found to be primarily iron (Fe) and oxygen (O), with a small bit of carbon (C) mixed in. The red layers were nanocomposites with a high aluminum (Al) and silicon (Si) content as well as Fe, O, in a C matrix. The number of Fe atoms was found to be about 2/3 the number of O atoms, indicating the Fe is apparently oxidized in the Fe2O3 state. Al was present 3 times as frequent in the red chips as O, showing it apparently was not oxidized.
Figure 1. Fragments of nano-Thermite found as microscopic red-gray chips throughout the dust at the World Trade Center. The gray surfaces were identified as primarily iron oxide (Fe2O3) covering the outside of the chips, and the red chips were identified as aluminum (Al) mixed with silicon (Si) and Fe2O3, clearly explosive at higher temperatures.
The red chips clearly contain nano-thermite, a nano-mixture of Al and Fe2O3 ripe for the very energetic chemical reaction 2Al + Fe2O3 -> Al2O3 + 2Fe . For ordinary thermite which the Army has used since World War II the chemical reaction takes place above 900°C and it is typically used as an indendiary device. However, numerous laboratory test of this nano-thermite showed that reaction took place at 435°C or below, and the reaction was very explosive, quickly producing temperatures of 3000°C. The Fe-rich spherules described last chapter as being found throughout the World Trade Center dust were found to be produced in large number upon ignition.
So what brought the buildings down in the World Trade Center was nano-thermite. The obvious follow-up question is: who put it there? Nano-thermite only recently became available. The paper headed by Neils Harrit report references papers written in 2000 and 2001 at Lawrence Livermore Labs describing the ready availability of such material. Where else was it readily available?
This discovery of the "smoking bomb" of the the real cause of the collapses of the buildings has confirmed a much darker picture of the fall of the WTC on 9/11. All of the government investigations on these facts focused instead on the terrorists who were identified as hijacking the planes and their collaborators, when their murderous criminal actions were clearly insufficient to have brought the Towers down, and certainly did not cause the collapse of Building 7 ,,. Now a full criminal investigation as to who set this and who ignited this potent explosive material is sorely needed. We should pursue all these murderers to the "ends of the Earth" and bring them to justice.
 Crockett Grabbe, "World Trade Center Collapse," Laissez Faire City Times, written 9/22/01
 Steven E. Jones, "Why Indeed Did the WTC Buildings Completely Collapse," Journal of 911 Studies, 3, September (2006). Linked out of http://www.Journalof911Studies.com . [Earlier version in Griffin & Scott (eds.), 9/11 and the American Empire: Intellectuals Speak Out (Interlink Publishing, Northhampton, MA, 2006].
 Steven Jones, Jeffrey Farrer, Gregory Jenkins, Frank Legge, James Gourly, Kevin Ryan, Daniel Farmsworth, and Crockett Grabbe, "Extremely High Temperatures during the World Trade Center Destruction," Journal of 911 Studies, 19, January, (2008) online at http://www.journalof911studies.com/articles/WTCHighTemp2.pdf
 Kevin R. Ryan, "The Top Ten Connections between NIST and Nano-thermite," The Journal of 911 Studies 22, July, 2008. Linked out of: http://www.Journalof911Studies.com .
 Niels H. Harrit, Jeffrey Farrer, Steven E. Jones, Kevin R. Ryan, Frank M. Legge, Daniel Farnsworth, Gregg Roberts, James R. Gourley and Bradley R. Larsen, "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe," The Open Chemical Physics Journal, 2, 7-31 (2009). Online at: http://www.bollyn.com/public/Active_Thermite_at_WTC.pdf
 Jim Hoffman, "Explosives Found in World Trade Center Dust," online at http://www.911research.wtc7.net/essays/thermite/explosive_residues.html
 NIST Investigation Committee, "Final Report on the Collapse of the World Trade Center Towers," 2005.
 NIST Investigation Committee, "Final Report on the Collapse of Building 7 of the World Trade Center," 2008.
 David Ray Griffin, The Mysterious Collapse of World Trade Center 7, (Olive Branch Press, Northampton, MA, 2010).