ROLLING ARRIVAL Navy. Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, arrives at the National Mall to give remarks at the Rolling Thunder event in Washington, D.C., May 29, 2011. Rolling Thunder is an annual event in which thousands of veterans ride motorcycles through the city to call attention to prisoners of war and those missing in action. SHARE: Download: Full Size (0.09 MB) Credit: VIRIN: 004541-M-IVV54-890.jpg Photo Gallery