911 Anniversary: America Remembers
Americans gather to remember the victims of Sept. 11.
9/11 Anniversary: America Remembers
President Barack Obama and first lady Michelle Obama pause for a moment of silence at the wreath laying ceremony at the Flight 93 National Memorial Sunday, Sept., 11, 2011 in Shanksville, Pa., on the 10th anniversary of the Sept. 11 attacks. (Pablo Martinez Monsivais/AP Photo)
