World Trade Center 7 didn’t collapse for ‘no apparent reason’

A post on Instagram has claimed that on 9/11, World Trade Center 7 collapsed “for no apparent reason”.

During the terror attacks of 11 September 2001, four planes were hijacked: two were flown into the Twin Towers, one into the Pentagon and another crashed in a field in Pennsylvania. Two planes were flown into the North and South towers, part of the World Trade Center complex of seven buildings. Both towers collapsed shortly afterwards. World Trade Center 7 was a 47-storey building in the complex, which was not directly hit by an aircraft, and also collapsed later that day.

There are a number of reasons this building collapsed on the day, despite not being hit by planes, which have been described by investigators, scientists and experts since.

According to the US government’s National Institute of Standards and Technology (NIST), which investigated the reasons behind the collapse for years, a number of fires are behind World Trade Center 7’s collapse.

NIST says that debris from the collapse of the North Tower ignited fires on at least 10 floors of World Trade Center 7, some of which burned out of control because the automatic sprinkler system for some floors had failed (partly due to city water lines damaged by the collapse of the Twin Towers).

Heat from the fires then caused steel support beams to expand which led to several floors collapsing. This then triggered a number of other structural failures, which eventually resulted in the whole building collapsing.

The theory that an explosion caused the building’s collapse was investigated, but no evidence of this was found.

It’s true that fire causing tall buildings to collapse is rare. NIST lead investigator Shyam Sunder told journalists at the time: “This is the first time that we are aware of, that a building taller than about 15 stories has collapsed primarily due to fires”.

We’ve written previously about other conspiracy theories relating to World Trade Center 7.