Four commercial airplanes were hijacked on 9/11, and three of them struck major targets in the United States.

Quick Scoop

Direct answer

  • Total planes hijacked: 4.
  • Planes that actually hit targets:
    • American Airlines Flight 11 hit the North Tower of the World Trade Center.
* United Airlines Flight 175 hit the South Tower of the World Trade Center.

* American Airlines Flight 77 hit the Pentagon.

* United Airlines Flight 93 crashed in a field near Shanksville, Pennsylvania, after passengers resisted the hijackers; it did not hit a building but was intended as a fourth target (likely in Washington, D.C.).

So if you mean “how many planes hit buildings,” the answer is three ; if you mean “how many planes were involved in the 9/11 hijackings overall,” the answer is four.

In forum discussions and quick polls, people often answer “3” if they’re only thinking of the towers and the Pentagon, and “4” when they remember Flight 93 as part of the attacks even though it crashed in a field.

Mini recap (for context)

  • 2 planes hit the Twin Towers in New York City.
  • 1 plane hit the Pentagon near Washington, D.C.
  • 1 plane crashed in rural Pennsylvania after passengers tried to retake control.

These four coordinated hijackings on September 11, 2001, made up the full 9/11 attacks.

Note: Information gathered from public forums or data available on the internet and portrayed here.