WASHINGTON - SEPTEMBER 10: Tourists walk past a hazardous materials response vehicle on Capitol Hill September 10, 2011 in Washington, DC. Amid heightened security the Washington, DC area is ... more 
WASHINGTON - SEPTEMBER 10: Tourists walk past a hazardous materials response vehicle on Capitol Hill September 10, 2011 in Washington, DC. Amid heightened security the Washington, DC area is preparing to commemorate the 10th anniversary of the September 11, 2011 terrorist attacks on the Pentagon, the World Trade Center and on United Airlines Flight 93 in Pennsylvania. (Photo by Brendan Smialowski/Getty Images) less 
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Getty Images | Photo By Brendan Smialowski / Getty Images
Sat, Sep 10, 2011 4:42 PM EDT