WTC 7

WTC 7 was a skyscraper nearby the World Trade Center that collapsed on September 11, 2001, several hours after the Twin Towers fell. It was not hit by a plane but was severely damaged by debris and fires ignited by the collapse of the towers. The fires burned uncontrollably for hours, weakening the building’s structure until it ultimately collapsed in a controlled, symmetrical manner. The National Institute of Standards and Technology (NIST) concluded that WTC 7’s collapse was due to this combination of damage and fire, making it the first known tall building to collapse primarily because of uncontrolled fires.