Who was involved with September 11 2001?

The September 11, 2001, attacks were carried out by 19 terrorists associated with the extremist group al-Qaeda, led by Osama bin Laden. They hijacked four commercial airplanes, crashing two into the World Trade Center in New York City and one into the Pentagon in Arlington, Virginia, while the fourth, United Airlines Flight 93, crashed in Pennsylvania after passengers attempted to regain control. The attacks resulted in nearly 3,000 deaths and led to significant global political and military responses, including the U.S.-led invasion of Afghanistan.