Deborah Springs shops in a convenience store for food items after a power outage …
A San Diego police official directs traffic after a power outage Thursday, Sept. …
SAN DIEGO (AP) — A major power outage knocked out electricity to up to 5 million people in California, Arizona and Mexico on Thursday, bringing San Diego and Tijuana to a standstill and leaving people sweltering in the late-summer heat in the surrounding desert.
Two nuclear reactors were offline after losing electricity, but officials said there was no danger to the public or workers.
San Diego bore the brunt of the blackout that started shortly before 4 p.m. PDT (7 p.m. EDT, 2300 GMT); most of the eighth-largest U.S. city was darkened. All outgoing flights from San Diego's Lindbergh Field were grounded and police stations were using generators to accept emergency calls across the area.
Parts of Orange County regained power Thursday evening, but officials said most people would remain in the dark through the night.
The outage was likely caused by an employee removing a piece of monitoring equipment that was causing problems at a power substation in southwest Arizona, officials said. The power loss should have been limited to the Yuma, Arizona, area. The power company, Arizona Public Service, was investigating why the outage wasn't contained.
"This was not a deliberate act. The employee was just switching out a piece of equipment that was problematic," said Dan Froetscher, a vice president at APS.
Homes and businesses were darkened from southern parts of Orange County to San Diego to Yuma. It also affected cities south of the border across much of the state of northern Baja. Border officials said crossings into California are open.
"It feels like you're in an oven and you can't escape," said Rosa Maria Gonzales, a spokeswoman with the Imperial Irrigation District in California's sizzling eastern desert. She said it was about 115 degrees when the power went out for about 150,000 of its customers.
In Tijuana, people wandered out of their hot homes into the street to cool off while restaurants scrambled for ice to save perishable food.
In San Diego, the trolley system that shuttles thousands of commuters every day was shut down and freeways were clogged at rush hour. Trains were stopped in Los Angeles, an Amtrak spokesman said, because there was no power to run the lights, gates, bells and traffic control signals.
Police directed traffic at intersections where signals stopped working.
When a transmitter line between Arizona and California was disrupted, it cut the flow of imported power into the most southern portion of California, power officials said. The extreme heat in some areas also may have caused some problems with the lines, said Mike Niggli, chief operating officer of San Diego Gas & Electric Co.
"Essentially we have two connections from the rest of the world: One of from the north and one is to the east. Both connections are severed," Niggli said.
Niggli said relief was on its way, slowly. He said his 1.4 million customers may be without power until Friday.
Two reactors at the San Onofre nuclear power plant went offline at 3:38 p.m. as they are programmed to do when there is a disturbance in the power grid, said Charles Coleman, a spokesman from Southern California Edison. He said there was no danger to the public or to workers there.
The outage came more than eight years after a more severe black out in 2003 darkened a large swath of the Northeast and Midwest. More than 50 million people were affected in that outage.
In 2001, California's failed experiment with energy deregulation was widely blamed for six days of rolling blackouts that cut power to more than 3 million customers and shut down refrigerators, ATMs and traffic signals.
In Arizona, about half of Yuma County had power again Thursday evening after losing it earlier. Yuma County has about 200,000 residents and a little under half live in the city of Yuma.
"It's 113 degrees right now outside," said Yuma city spokesman Greg Hyland, who was sitting in the dark, answering calls.