SAN DIEGO – Utility crews brought electricity back to much of California, Arizona and Mexico on Friday, a day after a power outage left millions in the dark, paralyzed freeways and halted flights at San Diego's airport.
Officials, however, warned that the electrical grid was still too fragile after the outage and asked residents and businesses to go easy on — or even put off using — major appliances, such as air conditioners.
"Conservation will really help reduce the strain," said Stephanie McCorkle at the California Independent System Operator, which manages the power grid.
A decade after California faced rolling blackouts that shutdown everything from ATMs to traffic signals, Thursday's outage raised anew questions about the condition of the nation's electricity grid.
Authorities were focused Friday on trying to figure out how a mistake by a single Arizona Public Service Co. worker making a routine repair in Yuma, Ariz., could cascade across the Southwest.
"That work should not have caused this," said Damon Gross, spokesman for the Phoenix-based utility.
"Why it became so widespread is what we are going to work with the other utilities to investigate because the system should have isolated itself," he said. "It's designed to protect itself."
The outage came more than eight years after a more severe black out in 2003 darkened a large swath of the Northeast and Midwest, affecting more than 50 million people.
Electricity came back in San Diego early Friday, signaling that the blackout was essentially over because most people affected were in the nation's eighth-largest city.
Many spent the night struggling to fall asleep in the high temperatures.
Dan Williams lives in the hot desert of eastern California and usually looks forward to his business trips to San Diego. Not this time, he said, describing his stay at a motel like a camping trip.
"It was hot, there was no air. It was just miserable," said Williams, who slept with the door open.
Several construction workers at a clinic in San Diego stumbled back to work shortly before dawn.
Ed Harris grabbed a beer with his son and watched the traffic congestion from the patio of his San Diego home until he couldn't fend off sleep any longer and had to go back into his roasting residence.
"When I got up, my body left a big bed mark in a sweat ring," he said.
The lights came back on at his home at 2:18 a.m. His wife woke him up to set his alarm clock.
San Diego schools, state universities and community colleges in the area remained shuttered. Beaches were closed because the outage caused a 3.2-million gallon sewage spill.
The San Diego area was hit especially hard with power severed about 4 p.m. Thursday to all of San Diego Gas & Electric Co.'s 1.4 million household and business customers.
That left residents sweltering without air conditioners and paralyzing some freeway and airport traffic.
The outage extended across California's inland deserts, as far east as Yuma and into Mexico. The region is home to 6 million people, though it was impossible to say exactly how many had lost power.
Two reactors at a nuclear power plant along the coast went offline after losing electricity, but officials said there was no danger to the public or workers.
The outage occurred after an electrical worker removed a piece of monitoring equipment at a power substation in southwest Arizona, APS officials said.
"This was not a deliberate act. The employee was just switching out a piece of equipment that was problematic," said Daniel Froetscher, an APS vice president.
It's possible that extreme heat also may have caused some problems with the transmission lines, said Mike Niggli, chief operating officer of San Diego Gas & Electric Co.
During the night, much of San Diego was in darkness, and all outgoing flights grounded at Lindbergh Field. The airport was open and had power Friday but authorities said some airlines may have cancelled flights.
There were no immediate reports of major injuries connected with the outage.
Officials in San Diego and elsewhere said they were on alert but no major problems had arisen, including any signs of looting or other unrest.
There were reports of minor traffic accidents as the outage knocked out stoplights during rush hour.
Leah Walden said she saw about five fender-benders on her drive from her accounting job in suburban Spring Valley to a wedding-cake tasting in San Diego.
"People are irritated. They don't want to wait," said Walden.
The blackout extended south of the border to Tijuana, Mexicali and other cities in Mexico's Baja California state, which are connected to the U.S. power grid, Niggli said.
In Tijuana, people formed long lines outside convenience stores Thursday, trying to buy ice or take advantage of half-price beer. Many drank it on the streets or in parked cars with speakers booming loud music.
Cars also formed snaking lines at the few gas stations with generators that remained open and traffic snarled streets after traffic lights stopped working.
Jose Padilla Flores was one of the few people who still had electricity Thursday.
He offered to let people watch the telenovela on his television if they bought fried tacos and flavored water from his small restaurant "El Dorado" in the Independencia neighborhood.
"My female neighbors were the first ones to ask if I could let them watch the telenovela," said Padilla Flores, 35. "I thought that was a great idea to promote my business."
San Diego residents poured into the few bars that remained open downtown after dark, some donning reading lights on their heads like miners.
Two men carried flaming tiki torches — usually planted in backyards — to see their way.
___
Associated Press Writers contributing to this report include Elliot Spagat in San Diego; Gillian Flaccus in Orange County; Shaya Mohajer and Greg Risling in Los Angeles; Walter Berry, Paul Davenport and Michelle Price in Phoenix and Mariana Martinez in Tijuana.
