An electric cable carrying 11,000 volts exploded cutting the power in 3,000 homes in Bexleyheath.
What caused the fault in the 66,000 volt electricity substation in the EDF Energy compound in Lion Road, Bexleyheath is unknown, but is being investigated, said a spokesman for the fire service.
Four engines from Erith, Plumstead and Bexley were called at 11.47pm yesterday (November 18) to reports of an explosion.
It is thought the cable burned out and tripped the system disrupting the power supply to 3,000 EDF customers.
Engineers had restored power supplies to all customers by 1.03am today.
An EDF Energy spokesman apologised for the inconvenience caused by this incident.
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