Three of the hijackers carried copies of an identical handwritten letter ( in Arabic ) that was found in three separate locations : the first , in a suitcase of hijacker Mohamed Atta that did not make the connection to American Airlines Flight 11 that crashed into the North Tower of the World Trade Center ; the second , in a vehicle parked at Washington Dulles International Airport that belonged to hijacker Nawaf al-Hazmi ; and the third at the crash site of United Airlines Flight 93 in Shanksville , Pennsylvania
Flight 11
American Airlines Flight 11
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