Building 7

Building 7 was a 47-story skyscraper in New York City that collapsed on September 11, 2001, hours after the Twin Towers fell. Its collapse has led to various theories, but it was officially determined to be caused by fires ignited by debris from the North Tower’s collapse, which weakened its structural integrity. The fires burned for hours, and the building's unique design contributed to its failure. Building 7’s collapse was significant as it was the first known instance of a tall steel-framed skyscraper collapsing primarily due to uncontrolled fires.