WTC 7: Why the Third Building of 9/11 Became the Center of the Controlled-Demolition Allegation

At 5:20:52 p.m. on September 11, 2001, World Trade Center 7 collapsed in New York City. The 47-story building stood north of the main World Trade Center complex. No airplane struck it. After the two main towers fell, fires burned in WTC 7 for hours. When the building dropped almost straight down, many television viewers compared the image to controlled demolition, a method in which explosives are placed at structural points so a building falls into its own footprint.

Because WTC 7 was not the best-known image of September 11, many people know little about it. It contained offices for several government agencies, including the SEC, IRS, Secret Service, and New York City's emergency-management office. It stood over a Con Edison substation and used major transfer trusses at lower floors. These features made the technical investigation difficult. They also made public questions about design drawings, steel, fires, and the decision to abandon the building entirely reasonable.