Which group was responsible for the terrorist atacka an 911?

The terrorist attacks on September 11, 2001, were carried out by 19 militants associated with the extremist group al-Qaeda. Led by Osama bin Laden, al-Qaeda aimed to target symbols of American power and influence. The attackers hijacked four commercial airplanes, crashing two into the World Trade Center towers in New York City and one into the Pentagon, while the fourth plane, United Airlines Flight 93, crashed into a field in Pennsylvania after passengers attempted to retake control.