See the Wikipedia article on the collapse of the towers (http://en.wikipedia.org/wiki/Collapse_of_the_World_Trade_Center) and the NIST FAQ (http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm) and final report (.pdf -- http://wtc.nist.gov/NISTNCSTAR1CollapseofTowers.pdf ). The towers collapsed almost straight down, blowing what wasn't simply crushed out through the sides of the building. I'm amazed that you think it is suspicious that most of the contents of the building sustained damage. And they didn't test for thermite because they didn't have to, nor would it have been productive to do so. From the NIST FAQ: "NIST did not test for the residue of these compounds in the steel. The responses to questions number 2, 4, 5 and 11 demonstrate why NIST concluded that there were no explosives or controlled demolition involved in the collapses of the WTC towers. Furthermore, a very large quantity of thermite (a mixture of powdered or granular aluminum metal and powdered iron oxide that burns at extremely high temperatures when ignited) or another incendiary compound would have had to be placed on at least the number of columns damaged by the aircraft impact and weakened by the subsequent fires to bring down a tower. Thermite burns slowly relative to explosive materials and can require several minutes in contact with a massive steel section to heat it to a temperature that would result in substantial weakening. Separate from the WTC towers investigation, NIST researchers estimated that at least 0.13 pounds of thermite would be required to heat each pound of a steel section to approximately 700 degrees Celsius (the temperature at which steel weakens substantially). Therefore, while a thermite reaction can cut through large steel columns, many thousands of pounds of thermite would need to have been placed inconspicuously ahead of time, remotely ignited, and somehow held in direct contact with the surface of hundreds of massive structural components to weaken the building. This makes it an unlikely substance for achieving a controlled demolition. Analysis of the WTC steel for the elements in thermite/thermate would not necessarily have been conclusive. The metal compounds also would have been present in the construction materials making up the WTC towers, and sulfur is present in the gypsum wallboard that was prevalent in the interior partitions." ---The comforting thing about conspiracy theories is that they suggest that /someone/ is in charge and knows what is happening and why; for some reason that is a great deal more comfortable a thought for people than the idea that, in fact, /no-one/ is really in charge of many events, things happen truly randomly, and it is entirely possible that no-one on the planet actually has the real, true answer. Unfortunately, real life is under no obligation to conform to what we find more comforting, and it tends to be awkward with regard to our expectations. Edit to add: NIST is quite clear that they have not reached conclusions on WTC 7 and are looking at different hypotheses. Their report on the towers, on the other hand, is clear about its conclusions, detailed, and was composed by 85 different individuals. If you want to discount it, and still claim to have any respect for evidence, then you need to offer more than just a handwave. Why DID you bother asking, here, if your mind is already made up?