Observing Memorial Day--PICTURES

A Marine salutes as motorcycles drive past during the annual Rolling Thunder parade ahead of Memorial Day in Washington, Sunday, May 27, 2012. (AP Photo/Charles Dharapak)

Honor Guard members line up for the Memorial Day Observance at the Memorial Amphitheater ahead of President Barack Obama's arrival at Arlington National Cemetery, Monday, May 28, 2012. (AP Photo/Charles Dharapak)

President Barack Obama, and Maj. Gen. Michael S. Linnington, Commander of the U.S. Army Military District of Washington, lowers their heads during a wreath-laying ceremony at the Tomb of the Unknowns at Arlington National Cemetery on Memorial Day, Monday, May 28, 2012, in Arlington, Va. (AP Photo/Pablo Martinez Monsivais)

Motorcycles drive past on Memorial Bridge during the annual Rolling Thunder parade ahead of Memorial Day in Washington, Sunday, May 27, 2012. (AP Photo/Charles Dharapak)

President Barack Obama speaks at the Memorial Day Observance at the Memorial Amphitheater at Arlington National Cemetery, Monday, May 28, 2012. (AP Photo/Charles Dharapak)

American flags wave near the grave of Marine Lance Cpl. Michael Harris as the the sun rises over Georgia National Cemetery on Memorial Day, Monday, May 28, 2012, in Canton, Ga. Harris died Feb. 6, 2012, in North Carolina. ((AP Photo/David Goldman))

The grave of U.S. Marine Lance Cpl. Michael Harris is seen through an American flag as the the sun rises over Georgia National Cemetery Monday, May 28, 2012, in Canton, Ga. Harris died Feb. 6, 2012, in North Carolina. (AP Photo/David Goldman)

Andrea Bryson, of Woodbridge, Va., wipes tears from her face as she visits the grave of her husband, Army Col. Gene Bryson, in Section 60 at Arlington National Cemetery, in Arlington, Va., Monday, May 28, 2012. (AP Photo/Cliff Owen)

Honor Guard members depart after President Barack Obama speaks at the Memorial Day Observance at the Memorial Amphitheater at Arlington National Cemetery, Monday, May 28, 2012. (AP Photo/Charles Dharapak)