Vice President Joe Biden, left, and Interior Secretary Ken Salazar arrive at the Flight 93 National Memorial in Shanksville, Pa., for a memorial service, Tuesday, Sept. 11, 2012. (AP Photo/Gene J. ... more 
Vice President Joe Biden, left, and Interior Secretary Ken Salazar arrive at the Flight 93 National Memorial in Shanksville, Pa., for a memorial service, Tuesday, Sept. 11, 2012. (AP Photo/Gene J. Puskar) less 
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Associated Press | Photo By Gene J. Puskar
Tue, Sep 11, 2012 11:51 AM EDT