Firefighting crews continue to pour water onto a unit after a fire at a Chevron refinery on Tuesday, Aug. 7, 2012 in Richmond, Calif. The fire, which sent plumes of black smoke over the San Francisco Bay area, erupted Monday evening in the massive Chevron refinery about 10 miles (16 kilometers) northeast of San Francisco. It was out early Tuesday. (AP Photo/The Contra Costa Times, Aric Crabb)JASON DEAREN and TERRY COLLINS
RICHMOND, Calif. (AP) – Investigators were looking at how a small, seemingly insignificant leak at one of the country’s biggest oil refineries quickly unraveled into an intense fire that sent acrid black smoke into the sky and hundreds of people to hospitals with health complaints.
The leak started as a drip at about 4:15 p.m. Monday, officials said. Chevron – which is required to “immediately” notify the public of any gas leak, fire or oil spill, according to state law – did not consider it an immediate danger to residents nearby.
“At that point in time, there really wasn’t anything we could advise the community to do,” said Mark Ayers, the refinery’s fire chief. “We surely wouldn’t advise anybody to shelter in place.”
The company’s engineers began stripping away insulation on the leaky pipe to investigate the source, which released a vapor of a flammable substance similar to diesel. About two and a half hours later, a conflagration had officials scrambling to warn residents to stay inside.