Power was restored sooner than expected for 1.4 million Southern California residents, who lost electricity in massive blackouts Thursday. Power officials are now saying sewage spills caused by the outage may have contaminated drinking water in high elevation areas. Residents of those areas are being warned to boil their water.
Most of the people affected were San Diego Gas & Electric customers, but as power outages swept Coachella Valley, southern Orange County and parts of Mexico, the number of residents without power rose to 5 million.
Mexico's electrical utility says the lights are now on for about 1.1 million customers, or about 97 percent of those who lost power. A few industrial clients are still without it.
Power has also been restored to all 56,000 customers in Yuma, Ariz.
Electricity is back in San Diego, but city schools, state universities and community colleges in the area are closed for the day.
The loss of electricity contributed to huge financial losses for grocers and restaurants that were unable to refrigerate their goods during the outage.
Brian McGray says he threw out $1,500 worth of steak, along with chicken, cheese and eggs at The Riders Club Cafe in San Clemente.
Darren Gorski buys supplies for The Fish Market in San Diego and spent the night watching thermometers on five insulated refrigerators full of seafood.
He says $50,000 in fish survived the outage, but that he lost thousands in dairy products.
The outage also cut power to sewage pumps in San Diego. More than 2 million gallons of raw sewage has spilled into the ocean and onto some beaches.
Mark McPherson is San Diego County's chief of land and water quality, he says the Department of Environmental Health has closed portions of the coast line due to massive sewage spills.
"One of them is 1.9 million gallons that went into Los Penasquitos Lagoon, which empties into the Pacific Ocean at Torrey Pines State Beach. And the Department of Environmental Health has issued closure for the beaches five miles south and north of that point where it comes into the ocean."
McPherson says a second spill let 120,000 gallons of sewage pour into the Sweetwater River, which empties into San Diego Bay. Two nearby parks have been closed.
No homes are currently affected by the spills but beach and park closures are expected to continue throughout the weekend.
Erin Coller, a spokeswoman for SDG&E, said the overall power system is still fragile, meaning customers should try and conserve energy.
“There was an issue on the interconnected grid with a major transmission outage in Western Arizona that caused a loss of power to Southern California," Coller said.
"Then shortly afterward the San Onofre Nuclear Generating Station went offline. So as a result we didn’t have adequate resources on our system to keep the power on across our service territory.”
The outage triggered a shutdown of San Onofre's two nuclear reactors. John Wayne Airport was not affected by the power outage, but the San Diego International Airport's air traffic control tower no longer had power and operations there were halted except for inbound flights, which stopped at 6:30 p.m.
Amtrak spokesman Marc Magliari says two Pacific Surfliner trains couldn't continue southward past Los Angeles after power was lost Thursday afternoon.
Officials at Phoenix-based Arizona Public Service Co. say the outage occurred after an electrical worker removed a piece of monitoring equipment at a substation.
According to the Arizona Daily Star, Mike Niggli, chief operating officer of SGD&E, said, "To my knowledge this is the first time we've lost an entire system."
It's still unclear how many power customers elsewhere are still without power.
The Associated Press contributed to this story.