Americans Observe Memorial Day

U.S. President Barack Obama lays a wreath at the Tomb of the Unknown Soldier during the Memorial Day observance at Arlington National Cemetery, May 30, 2016.

Vietnam war veterans among other guests listen to U.S. President Barack Obama at the Memorial Day observance at Arlington National Cemetery in Washington, May 30, 2016.

Participants in the annual Rolling Thunder motorcycle rally ride past Arlington Memorial Bridge, Washington, May 29, 2016.

Thousands of U.S. and British flags are placed in memory of fallen soldiers near the Reflecting Pool in Washington, May 29, 2016.

Christian Jacobs, 5, of Hertford, N.C., dressed as a Marine, pauses at his father's gravestone on Memorial Day at Arlington National Cemetery in Arlington, Virginia. Christian's father Marine Sgt. Christopher James Jacobs died in a training accident in 2011.

A woman carries red roses as she walks among graves on Memorial Day at Arlington National Cemetery, May 30, 2016.

Actor and co-host Gary Sinise hugs veteran Jack Farley after paying tribute to him at the 27th National Memorial Day Concert in Washington. Farley, who was wounded in combat during the Vietnam War, received four bronze stars and two purple hearts.

Renee Fleming performs at the 27th National Memorial Day Concert in Washington, May 29, 2016.