Residents of the Pacific Northwest struggled to stay warm Saturday after the worst windstorm in more than a decade knocked out power to more than 1.5 million homes and businesses and killed at least six people.

More than 600,000 customers in Washington and Oregon still had no power Saturday, and utilities said some might have to wait into next week for their lights to go back on.

Washington Gov. Chris Gregoire declared a state of emergency, and with temperatures expected to drop over the weekend, officials warned people not to use outdoor grills, propane heaters or other carbon monoxide-producing equipment indoors.

Firefighters in Kent found 33 people from four families suffering from carbon monoxide poisoning Friday night, fire Capt. Kyle Ohashi said. They had taken their barbecues inside to cook or heat their apartments as temperatures dipped into the 30s.

All were expected to survive after treatment, Ohashi said.

In Oregon, a family of six was sickened by carbon monoxide from a generator set up in a garage in Gresham, police said. Three children were hospitalized in critical condition late Friday, while one child and both parents were listed in good condition.

Wind gusted to a record 69 mph early Friday at Seattle-Tacoma International Airport, breaking the old mark of 65 mph set in 1993. Wind was clocked at 113 mph near Mount Rainier.

Power was knocked out at one of the airport's concourses, canceling dozens of flights. Flights were also canceled at Portland International Airport in Oregon, and Amtrak canceled service between Seattle and Portland because downed trees and mudslides blocked the tracks.

Two people were killed in Washington 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. On the Oregon coast, an elderly couple died in a fire caused by candles they were using for light.

Puget Sound Energy, Washington's largest private utility, had restored power to about 200,000 customers overnight but 500,000 were still without power Saturday, company spokeswoman Dorothy Bracken said.

It would be "several days — definitely through the weekend," before everyone was restored, PSE spokeswoman Martha Monfried said. The utility had lost more than half of its transmission system, and crews struggled in the mountains to reach downed lines that carry the electricity from Columbia River dams.

More than 60,500 customers of Seattle City Light remained without power Saturday, down from a peak of 175,000, and 15,000 were still blacked out in the Snohomish County Public Utility District north of Seattle.

In Oregon, Portland General Electric said it had about 82,000 customers without power Saturday morning, while Pacific Power had said late Friday it was down to 53,000.

The storm was the most intense to hit the region since the Inauguration Day storm of Jan. 20, 1993, which killed five people and caused about $130 million in damage, said Clifford F. Mass, a University of Washington atmospheric sciences professor.