LOS ANGELES -- Power has been fully restored for tens of thousands of people in Southern California following a weekend blast and fire at a power station in the San Fernando Valley, officials said, CBS Los Angeles reports.

The Los Angeles Department of Water and Power said Sunday that electricity had been fully restored following the incident Saturday.

The fire at the power station in the Northridge area left nearly 94,000 without power by Sunday morning, and had impacted upwards of 140,000 customers initially.

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The LA Department of Water and Power said repairs continued Sunday but that the outage ended by mid-morning. Crews worked through the night to fix conductors, circuit breakers and transformers damaged in the blaze.

The fire at the station in the Northridge/Reseda area involved equipment that carries high-voltage electricity and distributes it at lower voltages, the department said.

The department shut off power to the station as a precautionary move, and began restoring service once the flames were out.

The fire's cause is under investigation.

The outage came as much of California baked in heat that broke records. A record that stood 131 years in Los Angeles was snapped when the temperature spiked at 98 degrees downtown.

Shortly after the blaze broke out, crews found a huge container of mineral oil that is used to cool electrical equipment on fire, Fire Department spokesman Brian Humphrey said.

"These were fierce flames, with smoke towering more than 300 feet into the sky," he told the Los Angeles Times.

No one was injured.

During the outage, cooling centers were opened for residents left without air conditioning. Firefighters rescued people who were stranded in elevators, Humphrey said.

People reported losing power in neighborhoods including Porter Ranch, Winnetka, West Hills, Canoga Park, Woodland Hills, Granada Hills, North Hills, Reseda and Chatsworth.