The longest warning NORAD received of the hijackings was some eight minutes for American Airlines Flight 11, the first flight hijacked. The FAA alerted NORAD to the hijacked Flight 175 at just about the same time it was crashing into the World Trade Center's South Tower. The FAA notified NORAD of the missing – not hijacked – Flight 77 three minutes before it struck the Pentagon. NORAD received no warning of the hijack of United Flight 93 until three minutes after it had crashed in Pennsylvania.