NIST says that the damage to WTC7 was negligible and had no bearing on the collapse at all, Fire alone caused it to collapse. Don't you read and believe what the NIST tells you? You must believe it if it is your evidence. You can't refuse parts of it and say they were wrong about structural damage to WTC 7 and at the same time say they are correct. I have already proven that EVERY SINGLE skyscraper that ever caught on fire DID NOT COLLAPSE. Only 1 skyscraper in the history of mankind has ever officially collapsed from fire alone. Only one. All other skyscrapers have endured more damage, longer fires and stood up and in fact are being used to this day. All of them!! So you telling me that an unchecked fire burning for 7 hours statistically has a likely chance of collapsing is PURE IGNORANCE OF THE FACTS. The facts are and the statistics will bear this out that the most likely scenario from a unchecked fire is a burned out building, but a standing burned out building.Take a look at that NIST link I provided earlier. It talks about certain highrise collapses and the various construction types used in the various buildings. It may give you some more answers to your questions. Building 7 was hit with pieces of falling tower but parts of it burnt out of control for upwards of 7 hours. If you subjected virtually any steel frame structure to similar conditions, I would be willing to bet it will collapse more often than not. Not every time necessarily, but more often than not (I've got the statistics on my side! lol!).