Two planes hit the Twin Towers of the World Trade Center on September 11, 2001:

• American Airlines Flight 11 was flown into the North Tower at 8:46:30 a.m.
• United Airlines Flight 175 struck the South Tower about sixteen and a half minutes later at 9:02:59 a.m.

Both were commercial passenger jets hijacked by terrorists in coordinated attacks. The impacts caused massive fires and structural damage that led to the collapse of both towers within two hours.