The 21st anniversary of the attacks of 11 September 2001 is approaching. A date that has shocked the whole world of air transport and beyond. It was a Tuesday. A typical hot day in late summer here in Italy. Across the Atlantic Ocean 19 al-Qaeda terrorists boarded 4 airliners of United Airlines and American Airlines and wrote a sad page in global history.

Once the aircraft were hijacked: an American Airlines Boeing 767 (flight AA11) with 92 people on board crashed into the North Tower of the World Trade Center in New York, a 410-meter high building consisting of 110 floors. Between the general disbelief and the terror of passersby, television stations around the world stopped normal programming to broadcast live from the "Big Apple". Soon after, under the gaze of hundreds of millions of spectators, another plane hit the South Tower: it was a United Airlines Boeing 767 (flight UA175) with 65 people on board.

It was clear: it could not have been an accident, the world was witnessing an unprecedented terrorist attack. Meanwhile, another American Airlines Boeing 757 plane (flight AA77), with 64 people on board, crashed into the facade of the Pentagon in Arlington, the building of the American defense ministry. Finally, a fourth Boeing 757 aircraft (flight UA93) crashed to the ground in the countryside near Shanksville, Pennsylvania, thanks to the passenger revolt, perhaps saving the White House to which it was destined.

Suicide attacks claimed the lives of nearly 3,000 people. All 4 airliners were on their way to California, taking off from Boston, Dulles and Newark airports. Between the convulsion of the moment and the general confusion, all international civil air vehicles were forbidden to land on US soil for three days. Those already in the air were rejected or diverted to the airports of Canada or Mexico. The history of the world would change shortly afterwards with the start of the War in Afghanistan (2001-2021) by the United States, which led to the killing of the leader of al-Qaeda, Osama bin Laden, in 2011.

21 years after that global collective drama, conspiracy theories on collective drama go viral on the Internet. Always the same, still in circulation. Shared mainly on the web, they are echoed on social networks, where they are relaunched. The idea behind the 9/11 conspiracy theories is that those weren't hijacked airliners: the skyscrapers would not collapse, but would be demolished in a controlled manner, perhaps to cash in on the insurance premium.

The reality is different and there is a truth. The Twin Towers had a central cavity structure consisting of steel columns, which could not have prevented airliners from penetrating inside. Therefore, the collapse of the skyscrapers was not due to the mere impact of the aircraft, but to the fires that broke out soon after, which had weakened the steel structures, triggering the collapse. Now all that remains is to pray in memory of the victims.

On the same topic see also the article published by AVIONEWS.