LOS ANGELES - AUGUST 5:  Los Angeles police officers wearing contamination suits secure the area following the explosion of a "dirty bomb" during a simulated attack at a dock at the Port of Los Angeles on August 5, 2004 in Los Angeles, California. In the drill's scenario, a "dirty bomb" smuggled into the port in a shipping container exploded as a bus was driving by, releasing a plume of radioactivity. More than 850 civilian and military personnel representing more than 60 government agencies, community based and private-sector organizations are participating in the terror response drill, "Determined Promise 2004".       (Photo by David McNew/Getty Images)