The death toll from the Northwest's worst windstorm in more than a decade climbed to 10 Monday, while nearly a quarter million homes and businesses remained without power in hard-hit western Washington.

At least 100 people have developed symptoms of carbon monoxide poisoning blamed on the use of portable generators and charcoal grills used for light and heat during the blackout. Two of them were among Washington's eight deaths.

"We're dealing with a carbon-monoxide epidemic in Western Washington," said Dr. Neil B. Hampson of Virginia Mason Medical Center.

Two other deaths in Oregon were blamed on the storm that struck last Thursday.

Wind gusted to 113 mph during the storm near Mount Rainier and to a record 69 mph at Seattle-Tacoma International Airport. More than 1.5 million homes and businesses across the Northwest lost electricity at some point in the storm.

About 240,000 customers were still without power in western Washington, utilities reported, as temperatures were in the low to mid 20s over most of the affected area early Monday.

Batteries and fire wood were in short supply in places and motorists faced long lines at some filling stations.

On Sunday, a man and his dog were electrocuted when they stepped on a fallen power line while out for a walk in Gig Harbor, Pierce County sheriff's Detective Ed Troyer said. Troyer said residents had been clearing debris near the power line for days, unaware that it was live.

Washington Gov. Chris Gregoire declared a statewide disaster and the state National Guard was mobilized to help get fuel and supplies to hard-hit areas.