Twin Towers dominated the Manhattan skyline for three decades, but the 9/11 attack ended its reign by bringing down the skyscrapers. Until today, there are various theories on why the World Trade Centers fell.

Twin Tower Collapse Conspiracy Theories

On Sept. 11, 2002, Islamist terrorists hijacked four passenger planes. Nearly 3,000 individuals died in the coordinated attacks as the aircraft were flown into the World Trade Center, the Pentagon, and a Pennsylvania field. Just hours after the incident, a conspiracy theory surfaced online suggesting that the incident was an inside job.

David Rostcheck wrote online that the airplane's impact didn't blow up the World Trade Center. Another claimed the buildings were demolished, and while the planes hit the building and damaged it, explosives must have been placed inside the towers that brought them down.

Another theory suggested that the U.S. military fired missiles and struck the Pentagon. The administration was allegedly aware of the impending attack and didn't take action, and the orchestrated attacks were just a false-flag operation.

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Why Did the Twin Towers Fall

Despite the various claims about the collapse of the World Trade Center, subsequent investigations by the U.S. Federal Emergency Management Agency (FEMA) and the National Institute of Standards and Technology clarified that fire brought by the planes weakened the tower structures and it fell due to the weight of the collapsing floor. They concluded that flames that started in the structures after the aircraft made contact rather than a direct strike or the deployment of explosives were to blame.

Aluminum is one of the lightweight materials used to make aircraft. It makes sense the building wouldn't collapse if you compare the mass of an aircraft with that of a skyscraper more than 400 meters tall and made of steel and concrete.

The towers were built to withstand wind loads more than 30 times the aircraft's weight and would have been more than 1,000 times the airplane's mass. Nevertheless, the aircraft did dislodge fireproofing material coated on the steel columns and the steel floor trusses inside the towers. The steel was exposed due to the lack of fireproofing.

The supporting steel columns were structurally harmed by the collision as well. The weight carried by a few damaged columns is moved to neighboring columns. Due to their resistance to the initial hits, both towers survived and did not instantly fall.

One of the most popular 9/11 conspiracy theories holds that a bomb or explosives must have gone off within the buildings because the skyscrapers survived the initial hits. Videos of the towers rapidly crumbling downward after the collision, resembling a staged demolition, have given rise to these theories. However, they might have fallen in this manner without the use of explosives.

This was brought on by fire. It is thought that the fire resulted from burning leftover aviation fuel.

The stiff steel columns in the structures were pushed against by the thermal expansion of the floors in a horizontal and outward orientation, according to the FEMA study, which deflected them to some extent but prevented further movement.

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