SEATTLE (AP) - A fierce windstorm swept through the Pacific Northwest Sunday, killing two people in Washington state and leaving hundreds of thousands of customers without power. Hien Nguyen, 19, of Lacey, was killed around noon when a 120-foot fir tree blew down on his pickup truck, crushing the cab, Lt. Matt Koehler said. A 50-year-old Seattle architect died in an avalanche at the Crystal Mountain ski resort, about 65 miles southeast of Seattle near Mt. Rainier. He and another skier had hiked into a closed area when the avalanche struck at about 1:30 p.m. His identity was not released. Interstate 90, running between Seattle and Spokane, was shut down periodically Sunday as crews set smaller avalanches to remove the danger of large ones sweeping down onto the roadway, said Clarissa Lundeen, spokeswoman for the state Department of Transportation.