By Tennille Tracy

WASHINGTON--Tens of thousands of people have suffered power outages as Hurricane Sandy churns up the East Coast and more are expected as the storm prepares to make landfall early this evening.

More than 12,000 customers in New York have lost power, according to the U.S. Energy Department, with thousands more in New Jersey and Virginia operating without electricity, according to figures released Monday.

More than 36,000 customers in several East Coast states had lost power by early Monday, according to the latest figures from the Energy Department.

A state of emergency has been declared in affected states. The number of reported power outages at this point represents less than 1% of the customers in affected states.

The ability of power companies to restore electricity in the days ahead will depend on the severity of winds and flooding conditions, the Energy Department said.

Baltimore Gas & Electric said it can't do overhead work with bucket trucks if winds exceed 25 miles per hour.

BG&E said it first tries to reconnect power for hospitals and 911 call centers before shifting its attention to homeowners and other customers. It also places a first-step priority on handling safety issues such as downed power lines.

Orange & Rockland Utilities said "extensive" repair work could take up to 10 days.

Utility companies are lining up extra workers to help bring power back online once the storm passes through. Dominion Resources Inc. (D), which operates in Virginia and North Carolina, said it had requested additional crews from other states to help restore power.

Duke Energy Corp. (DUK) said it was making 1,200 workers available to other utilities to help restore power in Sandy's aftermath.

Write to Tennille Tracy at tennille.tracy@wsj.com

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