Emily Johnson sheds tears in front of the headstone for her older brother, Army 1st Lt. David Andrew Johnson, who was killed by an improvised explosive device in 2012. Johnson and other family members of fallen troops as well as thousands of volunteers were at the Arlington National Cemetery, Va., on Dec. 12, 2015, for Wreaths Across America Day, an event to honor veterans during the holidays. (U.S. Air Force photo/Sean Kimmons)