Eighteen people were unaccounted for a day after a terrifying wall of mud and debris destroyed as many as 30 homes in rural northwestern Washington state and killed at least three people, authorities said Sunday.
Authorities said that because of the quicksand-like mud, it was too dangerous to send rescuers into the stricken area. Searchers instead flew over the one-square-mile mudslide in helicopters, looking for signs of life.
Some of the missing may have been able to get out on their own, authorities said.
Snohomish County Fire District 21 Chief Travis Hots said at a news briefing that authorities suspect "people are out there, but it's far too dangerous to get responders out there on that mudflow."
Authorities were also trying to determine how to get responders on the ground safely, Hots said, likening the mudflow to quicksand.
Officials described the mudslide as "a big wall of mud and debris" that blocked about one mile of State Route 530 near the town of Oso, about 55 miles north of Seattle. It was reported about 60 feet deep in some areas.
Authorities believe the slide was caused by groundwater saturation from recent heavy rainfall.
Several people — including an infant — were critically injured and as many as 30 houses were destroyed. The slide wiped out one neighborhood; "that neighborhood is not there anymore," Hots said.
Hots said the number of missing is fluid and could change because some people may have been in cars and on roads when the slide hit just before 11 a.m. Saturday.
The mud was so thick and deep that searchers turned back late Saturday after attempting to reach an area where voices were heard crying for help.
Rescuers couldn't hear any signs of life once they got closer, and the decision was made to retreat due to safety concerns, Hots said.
The slide blocked the North Fork of the Stillaguamish River. With the water rising rapidly behind the debris, authorities worried about severe downstream flooding and issued an evacuation notice Saturday.
Authorities said Sunday that residents could return home during daylight hours.
John Pennington, director of Snohomish County Emergency Management Department, said they were dealing with "a disaster within a disaster" — both the mudslide and the potential for a flash flood. He said there were concerns that the water could break downstream, as well as back up and flood areas upstream.
The Snohomish County sheriff's office reported that two people had been killed at the scene. Authorities later said one of the people who had been rescued died at a hospital.
Shari Ireton, a spokeswoman for the Snohomish County sheriff's office, said Sunday a total of eight people were injured.
A 6-month-old boy and an 81-year-old man remained in critical condition Sunday morning at Harborview Medical Center in Seattle. Hospital spokeswoman Susan Gregg said two men, ages 37 and 58, were in serious condition, while a 25-year-old woman was upgraded to satisfactory condition.
Bruce Blacker, who lives just west of the slide, doesn't know the whereabouts of six neighbors.
"It's a very close knit community. They're all our neighbors," Blacker said as he was waiting to talk with Washington State Patrol at an Arlington roadblock before troopers let him through. There were almost 20 homes in the neighborhood that was destroyed, he said.
"I'm hoping for the best," he said.
The American Red Cross set up at the hospital, and evacuation shelters were created at Post Middle School in Arlington and the Darrington Community Center.
One eyewitness told the Daily Herald that he was driving on the roadway and had to quickly brake to avoid the mudslide.
"I just saw the darkness coming across the road. Everything was gone in three seconds," Paulo Falcao told the newspaper.
Search-and-rescue help came from around the region, plus the Washington State Patrol and the Army Corps of Engineers. More than 100 were at the scene.
The National Weather Service issued a flash flood watch for Snohomish County through Sunday afternoon.
People who live in the North Fork's flood plain, from the small communities of Oso to Stanwood, were urged Saturday to flee to higher ground.
Snohomish County officials said Sunday morning that residents could return during daylight hours but that they would likely reissue the evacuation order Sunday night.
Dane Williams, 30, who lives a few miles from the mudslide spent Saturday night at a Red Cross shelter at an Arlington school.
He said he saw a few "pretty distraught" people at the shelter who didn't know the fate of loved ones who live in the destroyed neighborhood.
"It makes me want to cry, just looking at them," Williams said Sunday.
Washington Gov. Jay Inslee proclaimed a state of emergency.
Bart Treece, spokesman for the Washington State Department of Transportation, said he didn't know how long the two-lane rural road would be closed. Drivers were advised to find another way to get between Darrington and Arlington, he said.
Snohomish County authorities said the area has a history of unstable land. He said a slide also happened there in 2006.
Pennington said Saturday's slide happened without warning.
"This slide came out of nowhere," he said.
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