Presiden Obama, flanked by Defense Secretary Leon E. Panetta (left) and Gen. Martin Dempsey, bows his head at the Pentagon Memorial during a ceremony to mark the 11th anniversary of the Sept. 11 attacks. (AP Photo/Carolyn Kaster)
An honor guard bugler plays taps at the the Pentagon Memorial as the 10th anniversary of the Sept. 11 attacks is observed at the Pentagon outside Washington on Sunday, Sept. 11, 2011. (AP Photo/Charles Dharapak)
A Secret Service countersniper team looks out from atop the Pentagon during a 10th-anniversary remembrance ceremony at the Pentagon Memorial in Washington on Sunday, Sept. 11, 2011. (AP Photo/J. Scott Applewhite)
Soldiers lay wreaths at the Pentagon Memorial on the benches bearing the names of the victims during the 10th-anniversary ceremony of the Sept. 11 attacks at the Pentagon outside Washington on Sunday, Sept. 11, 2011. (AP Photo/Charles Dharapak)
Wreaths laid by a service member during the commemoration of the Sept. 11, 2001, attack on the Pentagon sit on each of the 184 memorial benches of the Pentagon Memorial in Arlington on Sunday, Sept. 11, 2011. (T.J. Kirkpatrick/The Washington Times)
Wreaths laid by a service member during the commemoration of the Sept. 11, 2001, attack on the Pentagon sit on each of the 184 memorial benches of the Pentagon Memorial in Arlington on Sunday, Sept. 11, 2011. (T.J. Kirkpatrick/The Washington Times)
Tricia Martin and her fiance, Dan Holdridge, both of Stonington, Conn., walk on Sunday, Sept. 11, 2011, in the Pentagon Memorial following the 10th-anniversary commemoration of the Sept. 11 attack on the Defense Department headquarters in Arlington. Mr. Holdridge survived the attack on the Pentagon after being caught under the collapsing building while working in the Naval Command Center. He said that "10 years doesn't mean much of anything — the trauma was overwhelming." (T.J. Kirkpatrick/The Washington Times)
Wreaths laid by a service member during the commemoration of the Sept. 11, 2001, attack on the Pentagon sit on each of the 184 memorial benches of the Pentagon Memorial in Arlington on Sunday, Sept. 11, 2011. (T.J. Kirkpatrick/The Washington Times)
Sara Guest (left) and her husband, Jackson, comfort Toni Guest, 21, all of Watkinsville, Ga., as the family visits the Pentagon Memorial on Sunday, Sept. 11, 2011, following the commemoration of the Sept. 11, 2001, attack on the Pentagon in Arlington. Sara Guest's sister, Leslie Whittington, was killed in the attack, along with Leslie's husband, Charlie, and their daughters, Zoe Falkenberg, 8, and Dana Falkenberg, 3. (T.J. Kirkpatrick/The Washington Times)
