Today is the 20th anniversary of what is now commonly known as 9/11.
It was September 11th of 2001 that 19 militants associated with the Islamic extremist group al Qaeda hijacked four planes in a suicide mission.
Two flew into the twin towers of the World Trade Center in New York City.
A third crashed into the Pentagon, and the fourth plane crashed in a field in Pennsylvania.
That’s because passengers on the fourth plane, Flight 93, fought back against the hijackers, forcing the plane to crash into a field rather than a building.
The death toll was almost 3,000 people from 93 different countries.
Twenty-four Canadians died in the 9/11 attacks, and when the United States closed its airspace, hundreds of planes were diverted to Canadian airports.

Several communities across Canada today (sat) will mark the 20th anniversary of the 9/11 terrorist attacks. The U.S. Embassy in Ottawa will be holding an event at the Beechwood 9/11 Memorial. Gander, Newfoundland will unveil a new 9/11 memorial tomorrow. A number of planes landed in Gander after U.S airspace was closed following the attacks.