A San Bruno police officer stands guard next to burned homes near the epicenter of the gas line explosion that devastated a neighborhood near San Francisco International Airport September 24, 2010 in San Bruno, California. Work crews continue to sift through rubble and residents are beginning... A San Bruno police officer stands guard next to burned homes near the epicenter of the gas line explosion that devastated a neighborhood near San Francisco International Airport September 24, 2010 in San Bruno, California.