A fire that ignited in an underground natural gas storage area in the San Francisco Bay Area prompted the evacuation of thousands of residents, as Chevron emergency crews worked Thursday to purge gas from a pipeline and prevent an explosion, officials said.
The evacuation order was issued late Wednesday for about 1,400 homes near the pipeline in Bay Point after the fire started. About 4,000 people were affected.
Workers spent the night purging natural gas from the pipeline and planned to inject nitrogen "which will extinguish the fire" burning in the underground vault, Chevron spokesman Cary Wages told reporters.
The fire began after a grass fire Wednesday evening near the pipeline that crews quickly extinguished, said Terence Carey, an assistant fire chief for the Contra Costa County Fire Protection District. About an hour later, another fire was reported in the underground vault that serves as a storage unit, he said.
"It was realized very quickly that there was a high probability of danger," Carey said, explaining the evacuation order for homes within a half-mile (0.8 kilometer) of the pipeline. Officials went door-to-door to tell people to leave their homes in the suburban area about 40 miles (65 kilometers) east of San Francisco.
KTVU-TV reported that many people slept in their parked cars at a light rail station while others parked and slept in outdoor parking lots. Evacuation centers were opened Thursday.
Officials hoped to start allowing people to return home within hours but said they would wait until the fire is extinguished.
In 2010, a Pacific Gas & Electric Co, natural gas pipeline exploded in San Bruno, south of San Francisco, killing eight people and destroying 38 homes. The utility was subsequently convicted by a federal court for violating pipeline safety regulations and fined $1.6 billion.