NORTHRIDGE ( — Fire crews put out an electrical fire at a DWP power plant in Northridge Saturday night.

LADWP said 140,000 customers were without power following the explosion. LADWP Tweeted after 10 p.m. that crews had restored power to nearly 50,000 customers, leaving 94,000 still without power.

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LA City Fire said neighbors heard a loud explosion. A loud bang about 7 p.m. Saturday. The fire sent massive plumes of black smoke into the sky. The smoke could be seen from several miles away.

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A DWP official said the explosion occurred at Receiver Station J — where they take the power in at a higher voltage and then distribute it to customers at a lower voltage. 50,000 to 60,000 gallons of mineral oil were burning at the receiver site. It was unclear as of Saturday night what sparked the explosion.

Firefighters had to de-energize the site and pour massive amounts of water and foam onto it. They said it does not appear to be a health hazard.

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About 90 firefighters were staged around the plant Saturday night to ensure that it didn’t start up again from mineral oil.