There will always be people who think the Moon landings were a hoax, that the Earth is flat, that vaccines cause autism, and that fire didn't cause the World Trade Center's buildings to collapse. This month, a group called Architects and Engineers for 9/11 Truth published a report from researchers at the University of Alaska Fairbanks about a "four-year computer modeling study on the collapse of World Trade Center Building 7," which was not hit by one of the jets piloted by al Qaeda terrorists.
The 47-story WTC 7 was the third skyscraper to be completely destroyed on September 11, 2001, collapsing rapidly and symmetrically into its footprint at 5:20 PM. Seven years later, investigators at the National Institute of Standards and Technology (NIST) concluded that WTC 7 was the first steel-framed high-rise ever to have collapsed solely as a result of normal office fires.
Contrary to the conclusions of NIST, the UAF research team finds that the collapse of WTC 7 on 9/11 was not caused by fires but instead was caused by the near-simultaneous failure of every column in the building.
I'm not an architect and I have not used my mechanical engineering degree since 1990 or so, so I am in no position to argue with Architects and Engineers for 9/11 Truth. But if I had to bet, I'd put my money on The National Institute of Standards and Technology, which investigated the matter in 2017 and concluded "WTC 7 collapsed because of fires fueled by office furnishings. It did not collapse from explosives or from diesel fuel fires."