Memorial Wreath President Barack Obama pauses for a moment of silence after laying a wreath at the Pentagon Memorial, Sept. 11, 2009, with Defense Secretary Robert Gates and Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff. The leaders were participating in a ceremony to honor the 184 victims killed when American Airlines Flight 77 crashed into the Pentagon during a terrorist attack 8 years ago. White House photo by Pete Souza SHARE: Download: Full Size (0.09 MB) Credit: Pete Souza VIRIN: 110911-O-PZ247-001.JPG Photo Gallery