President Obama, first lady Michelle Obama, former president George W. Bush, and Laura Bush salute the flag during 10th anniversary ceremonies at the National September 11 Memorial at the World Trade Center site in New York on Sept. 11. The 9/11 attacks changed life in the US forever, but 10 years after the devastating hit, New Yorkers have learned to live in a more dangerous world and are ready to move on. Allan Tannenbaum/Reuters
President Obama lays a wreath at the Pentagon Memorial on the 10th anniversary of the 9/11 attack on the Pentagon in Washington on Sept. 11. Kevin Lamarque/Reuters
President Obama places a wreath while first lady Michelle Obama watches as they visit the Flight 93 National Memorial, marking the 10th anniversary of the 9/11 attacks during ceremonies in Shanksville, Pa., on Sept. 11. Larry Downing/Reuters
Former New York Mayor Rudy Giuliani, who inspired so many after the tragedy of Sept. 11, 2001, speaks during ceremonies marking the 10th anniversary of the 9/11 attacks on the World Trade Center in New York on Sept. 11. Allan Tannenbaum/Reuters
Widow Nancy Gregory hugs her sons as they pay their respects to her husband, firefighter Ken Kumpel, at the National September 11 Memorial during ceremonies on Sept. 11. Mary Altaffer/Reuters
A tourist family stops to pause during the final moment of silence at 10:28 a.m., remembering the collapse of the North Tower, as commemorative services are displayed on the electronic billboards in Times Square, marking the 10th anniversary of the 9/11 attacks on the World Trade Center in New York on Sept. 11. Chip East/Reuters
Paul Simon performs during ceremonies marking the 10th anniversary of the 9/11 attacks on the World Trade Center in New York on Sept. 11. Allan Tannenbaum/Reuters
Former New York Governor George Pataki embraces a woman at the National September 11 Memorial on Sept. 11. The New York 9/11 memorial includes two plazas in the shape of the footprints of the twin towers with cascading 30-foot waterfalls. Around the perimeters of pools in the center of each plaza are the names of the victims of the 9/11attacks and an earlier 1993 attack at the trade center. Justin Lane/Reuters
The Tribute in Lights shines behind the Empire State Building seen from the Top of the Rock observation deck as it is illuminated over the skyline of lower Manhattan on Sept. 11. Lucas Jackson/Reuters
A giant US flag covers the field during ceremonies to mark the 10th anniversary of the 9/11 attacks before the NFL football game between the Dallas Cowboys and the New York Jets in East Rutherford, N.J., on Sept. 11. Brian Snyder/Reuters
US soldiers salute during a memorial ceremony to commemorate the 10th anniversary of the 9/11 attacks at Bagram airbase, north of Kabul, Afghanistan, on Sept. 11. Ahmad Masood/Reuters
Britain's Prince Charles (c.), Prime Minister David Cameron (r.), and US Ambassador Louis Susman stand after laying a wreath during the ceremony to commemorate the 9/11 attacks on the World Trade Center in New York at the memorial near the US Embassy in London on Sept. 11. Lewis Whyld/Reuters
Lighted structures simulating the twin towers are displayed during an event to mark the 10th anniversary of the 9/11 attacks on the World Trade Center at Trocadero square near the Eiffel Tower in Paris on Sept. 11. Gonzalo Fuentes/Reuters
Ground Zero victims: Some families of the Ground Zero victims are unhappy remains are being placed in the 9/11 memorial in New York.
The unidentified remains of those killed in the Sept. 11, 2001 attack on the World Trade Center in New York City were moved into a repository at the bedrock level of Ground Zero on Saturday after a procession through Manhattan streets.