Attendees bow their heads during the invocation at a ceremony posthumously awarding the Navy and Marine Corps Medal to Gunnery Sgt. Thomas Sullivan and Staff Sgt. David Wyatt at Ross’s Landing in Chattanooga, Tenn., May 7, 2017. Sullivan and Wyatt were posthumously awarded the medal for their actions during the July 16, 2015 shooting that occurred at the Naval Reserve Center Chattanooga that left two other Marines and a sailor dead. (U.S. Marine Corps Photo by Lance Cpl. Niles Lee/Released)