A major flaring event at the former Exxon Mobil refinery in Torrance triggered a shelter-in-place order for local residents and slowed traffic along the 405 Freeway as an enormous column of smoke and flames rose above the facility early Tuesday.
The flaring was caused by a widespread power outage that left more than 100,000 South Bay residents without electrical service, according to the Torrance Police Department and Southern California Edison.
One refinery employee was taken to a hospital for evaluation, fire officials said. Fire crews remained at the scene Tuesday morning to help refinery employees bring their units back online.
At 5:45 a.m., Torrance Fire Department units were dispatched to the refinery, which evacuated all non-essential employees, the Fire Department said in a statement. As a precautionary measure, Crenshaw and Del Amo boulevards bordering the facility on 190th Street were closed temporarily.
At around 6:40 a.m., Torrance city officials warned residents to remain in their homes, shut doors and windows and turn off air conditioners. The shelter-in-place warning was lifted around 7:30 a.m.
Television images showed large flames erupting from tall flare stacks at the refinery, which was sold this summer by Exxon Mobil to New Jersey-based PBF Energy and is now known as the Torrance Refining Co.
Areas that lost power Tuesday included Westmont, Hawthorne, Gardena, Torrance, Manhattan Beach and Redondo Beach, according to Southern California Edison. The power outages began around 5:40 a.m., officials said.
Most customers had power restored by about 7 a.m., said Paul Netter, a spokesman for Southern California Edison. The cause of the outage had not been determined, he said.
The refinery also lost power, officials said.
In a statement, Southern California Edison said it had "multiple teams mobilized to fully investigate the cause of the outage" and "regrets the inconvenience this incident caused."
All safety systems at the refinery operated properly, PBF Energy said in a statement. The company has begun restarting operations, a process that is expected to take several days and could include additional planned flaring, according to the company and Torrance police.
Fine-particle air pollution spiked to elevated levels in a residential area near the refinery early Tuesday, according to readings collected by the Coalition for Clean Air, an environmental group.
A portable real-time air-quality monitor deployed by the group detected an increase in levels of the lung-damaging pollutant PM2.5 to levels as high as 60 micrograms per cubic meter. Instantaneous readings above 60 are considered "high" by the U.S. Environmental Protection Agency, according to the group.
Air pollution monitors at the facility showed a one-hour increase in levels of fine particles, "but they did not exceed short-term unhealthy levels," said Sam Atwood, a spokesman for the South Coast Air Quality Management District.
By mid-morning Tuesday, air quality officials had received 15 complaints about the incident, Atwood said.
The Torrance refinery experienced two unplanned flaring events last month because of electrical problems, authorities said. A flaring event occurs when the plant sends excess hydrocarbon products to the flare stacks to be burned off, producing a large column of flame.
"Following the last outage, we initiated discussions with SCE [Southern California Edison] about improving their grid to the refinery and will obviously look to accelerate those discussions and action by SCE to provide more reliable electricity to the refinery and the community," PBF said in its statement.
In June, three workers were injured at the refinery when a 300-ton crane collapsed as it moved debris.
In February 2015, an explosion injured four contractors and destroyed the plant's pollution-control system, shutting down a portion of the refinery for months. The California Division of Occupational Safety and Health issued 19 citations to Exxon Mobil, which was fined $566,600.
The 750-acre refinery has more than 600 employees, as well as some 400 contractors who work there on a daily basis, according to PBF Energy. The facility produces gasoline, diesel fuel, jet fuel and liquefied petroleum gases.
Los Angeles Times staff writer Tony Barboza contributed to this report.
1:40 p.m.: This article was updated with information from a spokesman for the South Coast Air Quality Management District..
1:15 p.m.: This article was updated with air quality information.
12:55 p.m.: This article was updated with statements from PBF Energy and information about additional planned flaring.
9:50 a.m.: This article was updated with additional information from the Torrance Fire Department.
8:55 a.m.: This article was updated with details on past flaring events at the refinery.
7:45 a.m.: This article was updated with information from the Torrance Police Department and Southern California Edison.