President Barack Obama, Secretary of Defense Chuck Hagel, Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey and members of the audience salute and place their hands over their heart as the National Anthem is played during a remembrance ceremony to honor the victims of the 9/11 attacks on the Pentagon in Arlington, Va., on Sept. 11, 2013. Obama, Hagel and Dempsey joined family members of those killed in the terrorist attack twelve years ago to remember and mark the anniversary.