A deep freeze stretched from the Rockies to New England on Sunday as workers tried to restore power to tens of thousands of homes and businesses left dark by fierce wind that also was blamed for four deaths.

Rochester had a low of 10 degrees Sunday morning, and wind of up to 17 mph made it feel like almost 10 below zero, the National Weather Service said. In the Upper Midwest, the 8 a.m. reading of 2 below zero at Duluth, Minn., combined with 17 mph wind for a wind chill of 23 below.

As far south as Arkansas, Little Rock had a Sunday morning low of just 18. Farther west, Alliance, Neb., bottomed out at 8 below, the weather service said.

The frigid temperatures forced officials in Madison, Wis., which had a high of just 3 degrees on Saturday, to cancel the "Polar Plunge" into a lake, a fundraiser for the Special Olympics. Hayward had a low of 26 below zero on Saturday.

"We first really realized it was a problem when we cut the hole this morning and it immediately skimmed over with ice," Cheryl Balazs of the Special Olympics told WKOW-TV.

Utility officials in New York said crews would work through the weekend to restore power. Utilities reported at least 56,000 homes and business still without electricity Sunday, down from a peak of 328,000 customers blacked out Friday when wind gusted to 77 mph at Rochester.

Thousands of customers also lost power in Michigan, New Hampshire, Maine, and Vermont, where the National Weather Service reported a wind gust of 143 mph on Stratton Mountain.

Several states opened shelters, providing havens with light and heat for those without power.

"Most people tough it out the first night and then come in the second night," said Mark Bosma, spokesman for Vermont Emergency Management.

Trees toppled by the wind killed two motorists in New York and one in Massachusetts. Another was killed near Rochester when his vehicle slammed into a truck rig whose driver had stopped to clear storm debris from his windshield.

In addition, the body of a man was found Saturday in his home near Grand Rapids, Mich., apparently overcome by carbon monoxide from a generator, authorities said.