CROCKETT, Calif. (AP) – Officials were trying to determine if a 4.5 magnitude earthquake triggered an explosion at a fuel storage facility in the San Francisco Bay Area that started a fire and kept thousands of people in their homes for hours because of potentially unhealthy air. The earthquake struck about 15 miles southeast of the NuStar Energy fuel storage facility in Crockett. It occurred 15 hours before the fire Tuesday that consumed thousands of gallons of ethanol, a gasoline additive.