According to Ai..........other buildings were within 200 feet, i picked that distance to get a general overview why others didn't collapse from the intense heat........the video of the actual events.....the smoke and fire are two of the most distinguishing, graphic features, before they collapsed...

In 2001, within 200 feet of the North and South Twin Towers of the World Trade Center, there were five other buildings. These included the Marriott World Trade Center (3 WTC), the smaller 4, 5, and 6 WTC buildings, and the U.S. Customs House (7 WTC).