WASHINGTON (AP) — Pepco says it has restored power to all high-voltage transmission lines and all substations, a major step in getting power back to customers.

However, the utility says extensive damage caused by Friday’s storms means it could be a week before all customers have power restored.

Crews are arriving from the Carolinas Sunday, and mutual assistance crews from southern states will arrive Monday to help with the restoration effort.

As of 9 a.m. Sunday, nearly 350,000 Pepco customers were without power. Pepco has more than 780,000 customers in the district and part of Maryland.

Pepco says all water pumping plants have been restored.

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