PENTAGON OBSERVANCE Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, Defense Secretary Leon E. Panetta and Vice President Joe Biden watch the laying of memorial wreaths at the Pentagon 9/11 observance ceremony honoring the 184 victims killed when American Airlines Flight 77 crashed into the Pentagon during a terrorist attack 10 years ago. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 023256-R-TCP38-310.jpg Photo Gallery