A Puget Sound Energy spokeswoman said Friday the utility still has not determined what caused a Thursday.
The spokeswoman, Allison Stanford, said PSE will bring in out-of-state representatives from the transformer manufacturer to help utility investigators determine the fire's cause. Meanwhile, the Redmond Police Department issued a news release Thursday evening saying the blaze was caused by a "transformer failure" and that PSE would be investigating what caused the equipment to malfunction.
Stanford said it could be several days before PSE crews determine an official cause or are able to estimate the cost of the damage.
“We’ll know more as (crews) can get in and take a look,” she said.
The fire, which was first reported at around 12:30 p.m. Thursday and put out at about 2:30 p.m., flared up briefly around 5:30 p.m. Redmond Fire Department spokesman Jim Bove said the flare up was significantly smaller than the original blaze.
"I'm told it was maybe 1/10th the size of the original one and that it’s not uncommon—the equipment can take several days to cool off completely," he said in an email.
The fire, which caused 25,000 PSE customers to lose power Thursday, happened just two days after a substation outage near Northeast 24th Street in the Redmond/Bellevue area. Stanford said utility officials have not yet determined if the two incidents could be related.