SEATTLE, Wash -- Utility crews were working nonstop through the weekend to restore service to hundreds of thousands of people still without power after a windstorm hit Western Washington.

The storm was the worst in more than a decade, claiming four lives and sending several dozen people to a local hospital after they suffered carbon monoxide poisoning.

People struggled to stay warm as temperatures in the region were expected to drop into the 20s and lower 30s by Saturday night. The chance of rain or snow had diminished throughout most of the area, and temperatures would gradually increase through Sunday night, with Monday's highs returning to the 40s, said Johnny Burg, a meteorologist with the National Weather Service in Seattle.

"For some people that might not be much but it's definitely better than staying in the deep freeze," Burg said.

The storm hit late Thursday, and by early Friday winds gusted to a record 69 mph at Seattle-Tacoma International Airport, breaking the old mark of 65 mph set in 1993. Winds were clocked at 113 mph near Mount Rainier.

Power was knocked out early Friday to the south end of the airport terminal, as well as to a nearby Federal Aviation Administration air-traffic control office. More than 100 flights were canceled or delayed.

Two people were killed in traffic accidents involving windblown trees, while one died after getting trapped in her flooded basement. A fourth person was killed in his sleep by a tree that fell on his home.

At its peak, the storm knocked out power to more than a million people in Western Washington. Gov. Chris Gregoire declared a state of emergency Friday.

Officials warned people not to use outdoor grills, propane heaters or other carbon-monoxide-producing equipment indoors after firefighters in south suburban Kent found 33 people from four families suffering from carbon monoxide poisoning Friday night. They had brought their barbecues inside to cook food or heat their apartments as temperatures dipped into the 30s.

By Saturday, at least 59 people had been to Harborview Medical Center in Seattle for carbon monoxide poisoning. One person remained in serious condition, said Pamela Steele, a hospital spokeswoman.

Many of the victims were sent to Virginia Mason Medical Center for oxygen treatment in a hyperbaric chamber the size of a Boeing 737.

The hospital treated 48 victims in a 16-hour period since Friday, and five more being treated Saturday afternoon, said Dr. Neil Hampson, who specializes in hyperbaric medicine at Virgina Mason.

Victims range in age from one years old to 72, he said. "If you are seeking warmth until your power is restored, please seek out safe options, such as shelters, or the kindness of friends and family," Dorothy Teeter, interim director and health officer for Public Health Seattle & King County, said Saturday. "Carbon monoxide poisoning can kill you, and these cases we've seen show how serious the risk is."

Puget Sound Energy, the state's largest private utility, had restored power to about 260,000 customers by Saturday afternoon, leaving 440,000 still without.

It could be several days before everyone is restored, though. The utility suffered extensive damage to its transmission system. Crews struggled in the mountains to reach downed lines that carry the electricity from Columbia River dams.