UPDATED 10/29/12 10:04 a.m.:

RICHMOND, Va. (CBSDC/AP) — Dominion Virginia Power estimates up to 1 million customers could lose power over the next few days as Hurricane Sandy barrels by Virginia.

About 4,800 of the utility’s Virginia customers were without power Monday, up from 2,000 earlier in the day.

Dominion will get assistance from 2,000 crews that are arriving in Virginia to help with the anticipated outages.

Spokeswoman Alison Kaufmann tells WWBT-TV that the three-day window of the storm will make it difficult for crews to restore power until the winds have passed.

If the outages reach 1 million, Kaufmann says Sandy would likely be one of the worst storms on record as far as leaving people in the dark. About the same number of customers were without power after Hurricane Irene last year.

RELATED HURRICANE SANDY NEWS

Resources and Closings

Shelters

Power Outages

(TM and Copyright 2012 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2012 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)