Investigators say the substation holds about 30,000 gallons of oil. It's unclear how much of it has already burned off.

Crews have not determined the cause of the fire and are working to restore power to affected customers, officials with Oncor said.

A power substation fire in north Fort Worth, sparked by an explosion, has impacted 54 customers. Fire crews and Oncor are working to manage the situation safely, with no evacuations recommended.