A Southern California Edison transformer caught fire Thursday evening leaving thousands of Irvine residents in the dark, authorities said.
About 26,000 customers along Barranca Parkway and Sand Canyon Avenue were without power after a transformer caught fire around 5 p.m., officials said.
The cause of the fire is under investigation, said Edison spokesman Paul Netter.
The number of customers without electricity fluctuated until power was restored at 11:30 p.m., Netter said.
When fire crews responded to the blaze, they found 3,300 gallons of mineral oil burning in one of the transformers at the substation at 1582 Sand Canyon Ave., said Orange County Fire Authority Capt. Steve Concialdi.
"The fire was putting out thick black smoke that you could see for miles," he said.
Electric company representatives shut off power to nearby transformers to prevent the fire from spreading to other equipment and minimize the risk of electrocution, he said.
About 25 firefighters knocked down the fire within 50 minutes using a special fire engine that sprays foam, Concialdi said.
No injuries were reported.