ARLINGTON, Va –The President John F. Kennedy Eternal Flame at Arlington National Cemetery burns brightly before contractors install white fencing to block the public’s view of the site April 29, 2013. Repairs and upgrades to the flame include installing burners, an igniter, and new gas and air lines. Contractors estimate that work on the burner itself will take three weeks. (U.S. Army photo/Patrick Bloodgood)