President Obama, Secretary Panetta and First Lady Michelle Obama observe a moment of silence. President Barack Obama, right, Secretary of Defense Leon E. Panetta, center, and First Lady Michelle Obama observe a moment of silence after the president laid a wreath at a ceremony commemorating the 11th anniversary of the Sept. 11, 2001, terrorist attacks on the Pentagon on Sept. 11, 2012. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 349107-T-TJC64-194.jpg Photo Gallery