08/28/2011 03:40 pm ET | Updated Oct 28, 2011

National Grid: Crews 'Working Very Hard' To Restore Power To Hundreds Of Thousands

National Grid, a utility company that supplies electricity to 3.4 million people in the northeastern United States, is currently working to restore power to over 500,000 customers in four states who lost power in the wake of Hurricane Irene, a process that may take days, according to the company.

"Certainly we're looking at days as opposed to hours in terms of restoration, but how many days, I wouldn't want to venture to guess," Steve Brady, a spokesman for National Grid, told HuffPost.

Tom Zeller Jr., senior energy and environment reporter for The Huffington Post, reports that 213,000 National Grid customers in Massachusetts, 103,000 in New York and 3,200 in New Hampshire are without power. USA Today reports an additional 155,000 National Grid customers in Rhode Island are also affected, bringing the current total to over half a million.

Brady, who said that customers continue to report outages, added that crews must wait until storm conditions weaken to even begin assessing the damage from Irene, which on Sunday morning was downgraded from a hurricane to a tropical storm.

"Crews are working very hard, and they will work very long hours to the degree that they can do so safely," he said.

He advised that customers who are experiencing outages stay away from any downed power lines, adding that even wooden tree limbs can conduct electricity even if they are resting on one.

National Grid customers can call area-specific phone numbers to report outages. The company is also responding to customers via Twitter and Facebook.

So far, the storm has left over 4.5 million people -- from North Carolina to New Hampshire -- without power, according to The Weather Channel.

For the most recent news on Irene, read The Huffington Post's live blog.