President Barack Obama places a wreath at the dateline of the Pentagon 9/11 Memorial during a remembrance ceremony to honor the victims of the 9/11 attacks on the Pentagon in Arlington, Va., on Sept. 11, 2013. The president joined Secretary of Defense Chuck Hagel, Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey and family members of those killed in the terrorist attack twelve years ago to remember and mark the anniversary.