Facebook post falsely denies planes caused Twin Towers to collapse

A post on Facebook suggests that planes did not cause the World Trade Center’s Twin Towers to collapse in the 9/11 attacks. 

The post, which has over 1,500 likes, says: “If you really believe a little plane made this engineering marvel collapse twice you need to do some research. [sic]”

The text is written on top of a photo of one of the towers during its construction. We assume the text is referring to the collapse of each of the Twin Towers, rather than one of the towers collapsing twice.

Misinformation and conspiracy theories about 9/11 often circulate on social media. Full Fact has checked many false claims about the terrorist attacks, including claims that there were no plane parts found at the crash sites, World Trade Center 7 collapsed for no reason and that no plane hit the South Tower.

There is substantial evidence that structural damage, caused by the plane crashes and subsequent fires, led the buildings to collapse.

The US Federal Emergency Management Agency (FEMA) report says “burning jet fuel spread across several floors of the buildings” and ignited much of the contents of both buildings. The temperature of the fires is believed to have been similar to that of a “large commercial power generating station”, which can be at above 1000C.

According to the report, the “heat induced additional stresses into the damaged structural frames while simultaneously softening and weakening these frames”. Thermal expansion due to high temperatures caused the concrete floors to sag and the perimeter columns to bend. 

Once floors collapsed in the upper part of the buildings, the report says “it caused an immediate progressive series of floor failures” that accelerated as the mass of collapsed floors increased. The buildings collapsed after burning for 56 minutes in the South Tower and 102 minutes in the North Tower.

The report also says that the impact of the aircrafts being flown into the two buildings is not believed to have been sufficient to cause them to collapse without the ensuing fires, but adds that it is “extremely unlikely” the fires would have developed to this extent without an “unusual triggering event” such as the attacks. The planes disabled the structures’ two main fire protection systems and are believed to have dislodged the structural fireproofing.

Another investigation by the National Institute of Standards and Technology (NIST) also concluded that the collapse of the Twin Towers and World Trade Center 7 “resulted from structural damage from direct and indirect effects of aircraft impact and the ensuing fires.”

While it’s not clear exactly what this Facebook post is suggesting happened instead, others promoting similar conspiracies have suggested that the attacks were carried out using explosives or missiles. 

There’s no evidence that this is the case, whereas pictures and videos taken of the attacks show planes flying towards the two World Trade Centre towers and the Pentagon [viewer discretion advised].

Image courtesy of Michael Foran