UPDATE 2:20 pm: The AP reports that about 18 people are still unaccounted for after a massive mudslide in rural northwest Washington State killed at least three people and forced evacuations because of fears of flooding. Snohomish County Fire District 21 Chief Travis Hots said at a news briefing Sunday that "we suspect that people are out there, but it's far too dangerous to get responders out there on that mudflow."
Rescuers continued the search Sunday morning for survivors of a massive mudslide north of Seattle.
So far, three people are known dead, about a dozen were injured, and at least six homes were destroyed when the slide blocked the North Fork of the Stillaguamish River, which prompted an evacuation notice because water was rising rapidly behind the debris. The number of homes lost is expected to increase.
The rain-drenched landslide, which hit midday Saturday, completely covered State Route 530 near the town of Oso, about 55 miles north of Seattle. It was at least 135 feet wide and 180 feet deep, Snohomish County authorities said. Authorities worried about severe downstream flooding if water suddenly broke through the blockage.
Local rescue units, plus units of the Washington State Patrol and US Army Corps of Engineers, continued the search through Saturday night. Helicopters, hovercraft, and thermal imaging cameras have been part of the search-and-rescue effort.
"We have people who are yelling for our help, and we are going to take extreme risks," Snohomish County Fire District 21 Chief Travis Hots said at a news briefing late Saturday.
“This is a massive slide, and we are in a very, very fluid and unstable situation,” Chief Hots said. "This is still a rescue mission until we determine otherwise. We don't have a firm idea of how many people are out there."
The power, speed and severity of the slide were spectacular, as it swept over a 360-yard-long section of roadway with mud and debris up to 20 feet deep, the Seattle Times reported.
“In three seconds, everything got washed away,” Paulo de Oliveira, who was driving on Highway 530, told the newspaper. “Darkness covering the whole roadway and one house right in the middle of the street.”
“I came within about 50 feet of being washed out,” Mr. De Oliveira said. “Along the river, I saw one place where there were two homes and they were just gone. Nothing left but a portable toilet … destruction all around.”
Local authorities and the National Weather Service link the massive slide to saturating rains this month in Snohomish County, destabilizing the terrain.
State geologists are expected to analyze the scene for possible causes, the Daily Herald in Everett, Wash., reports.
The last rainfall in the county was reported Wednesday, with the last big rainfall on March 16, said Johnny Burg, a meteorologist with the National Weather Service in Seattle.
About 5.65 inches of rainfall have been recorded since the beginning of March, compared to the average total of 3.37 inches for this month. Higher areas generally get more rain, including nearly an inch about three days ago, Burg said. "They had more than double what Everett had.”
The American Red Cross set up operations at a local hospital, and evacuation shelters were created at a middle school and community center.
"This is the worst thing that's ever happened in our community," Trudy LaDouceur of the Darrington Fire District told the Daily Herald. “For all of us, even though we're small between Arlington and Darrington, we're all connected, we're all neighbors. We’ve all lost people today.”
This report includes material from the Associated Press.