UPDATE: Large Fire Hits Redmond Power Substation

Editor's note: This story was updated on Friday.

Fire and utility crews responded Thursday afternoon to a large transformer fire at a power substation in Redmond that belched thick, black smoke that could be seen from as far away as Seattle.

The blaze, reported at 12:30 p.m., knocked out power to 25,000 customers in Redmond, Kirkland and Woodinville, according to a spokeswoman for Puget Sound Energy. It was extinguished at approximately 2:15 p.m., and all power was restored at 3:15 p.m., according to PSE.

No injuries were reported in the fire at the substation at Willows Road N.E.

PSE spokeswoman Martha Monfried said 15,000 gallons of mineral oil that fill the 10-year-old transformer were burning, but the utility said the oil is not hazardous. Two other transformers were shut down as a precaution.

"In the last 40 years, we've never had anything like this happen," Monfried said. "So it's fairly unusual."

PSE has an environmental crew on the scene as a precaution, even though the mineral oil is not toxic. The oil is used to cool the voltage that comes through the transformer, she said.

Monfried said it's too soon to say what sparked the blaze.

Redmond firefighters were first to respond to a report of an explosion, said city fire spokesman Jim Bove. They had to call in a fire truck with foam from the Port of Seattle because water wasn’t putting out the flames. PSE could not confirm that an explosion took place.

Clark Masterson, who works near the substation, said he went to a Subway sandwich shop on Willows Road for lunch at 12:20 p.m. and saw flames 30 to 40 feet high.

“We could see them over the trees,” he said.

Bove said no one was on site at the time of the fire. Nearby buildings weren't evacuated, but some businesses shut down because they lost power.

Nothing criminal is suspected, but "we'll be investigating just to be sure," Bove said.