Update: 18 people were unaccounted for as of 10 a.m. Sunday. Rescue efforts continue amid difficult, dangerous conditions.

OSO — A hillside broke free Saturday morning, sending a wall of mud, boulders and trees into a country neighborhood built along a bend in the North Fork Stillaguamish River.

Three people are confirmed dead, and others may still be missing under the debris. Eight other people were injured, with at least three in critical condition at Harborview Medical Center.

“This is a very, very hard day,” said Candy Vincent, of Darrington. “We lost a lot of friends, a lot of people aren’t accounted for right now.”

The slide crushed at least six houses, carrying them in splinters across Highway 530. The slide, estimated to be at least 135 feet wide and 180 feet deep, stretches a mile from where it broke off from the north side of the river.

The slide happened about 10:45 a.m., 17 miles east of Arlington. Debris dammed the river, threatening to flood low-lying areas downstream when it breaks. Residents and businesses from Oso to Stanwood were told to seek higher ground until daybreak.

“This is the worst thing that’s ever happened in our community,” said Trudy LaDouceur, of the Darrington Fire District.

A search for life

Rescue efforts continued into the night even as the water rose behind the dam.

County emergency responders were standing by, as the situation created “a potential for a catastrophic flood event,” Snohomish County spokeswoman Rebecca Hover said.

As night fell, many people remained unaccounted for, LaDouceur said. The fire hall was filled with food, and an emergency shelter was set up at the community center.

“For all of us, even though we’re small between Arlington and Darrington, we’re all connected, we’re all neighbors,” LaDouceur said.

The slide hit right between the Oso and Darrington fire districts.

“We’ve all lost people today,” she said.

Crews likely will need to wait until Sunday to get a more accurate assessment of casualties and property damage, sheriff’s spokeswoman Shari Ireton said.

Rescue crews quickly blocked the highway, turning back traffic at Whitman Road before moving the roadblock further west as the flood threat built.

Help poured in from throughout Snohomish and Skagit counties. At least 100 men and women were involved in the emergency response, sheriff’s Lt. Rodney Rochon said.

Airspace above the landslide was closed to all but rescue helicopters, which scanned the ground below for survivors. Some people were hoisted to waiting ambulances.

Helicopters also flew the severely wounded to Harborview, while other victims were driven to hospitals in Arlington, Sedro-Woolley and Mount Vernon.

A 6-month-old boy was in critical condition at Harborview. The hospital also received four other patients, all men, from the slide. Two were listed Saturday evening in critical condition, and another was in serious condition.

At least five other people were taken to Cascade Valley Hospital. Two people were released after being treated for hypothermia and minor injuries.

“We’re in full crisis mode here,” Cascade Valley spokeswoman Jennifer Egger said. Roughly a dozen people could be seen in the waiting room from outside the hospital.

The American Red Cross set up a shelter to handle people displaced from the landslide at Post Middle School in Arlington. About 200 people were in that shelter Saturday night. Others were in a second shelter opened at the Darrington community center.

A steady stream of people dropped off emergency supplies at Cascade Valley, 330 S. Stillaguamish Ave. Van loads of food, blankets and other goods were brought to help victims.

One of those who came by was Amy Brindle, of Marysville, who dropped off water. She said her husband has a co-worker whose parents’ house was lost in the slide. The parents are in the hospital, but “they can’t find Grandma,” who also lived there, Brindle said.

Waiting for the flood

Downriver, in Arlington, city officials closed Haller Park and firefighters went to businesses, telling them to shut down and get folks to higher ground.

“We just don’t know when the log-jam is going to break. It’s big,” spokeswoman Kristin Banfield said.

State geologists are expected to analyze the scene for possible causes. 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 at Paine Field since the beginning of March, compared to the average total of 3.37 inches for this month. Higher areas, such as Darrington, however, generally get more rain, including nearly an inch about three days ago, Burg said.”They had more than double what Everett had,” he said.

With Highway 530 closed, Darrington is cut off from its main route to Arlington and I-5. An alternate route between Darrington and the freeway is via Highway 20 in Skagit County, which connects with Highway 530 north of Darrington.

Spokesman Bart Treece of the Washington State Department of Transportation says he doesn’t know how long Highway 530 will be closed.

Friends Vincent and LaDouceur were sitting in a truck outside the IGA, which was a quiet place to talk and cry.

Landlines were down in Darrington all day after the slide, and people were unable to reach family members to see if they were OK, Vincent said.

By Saturday evening, more food had already been donated than for any funeral, Vincent said.

“Everyone is pulling together, the whole community,” she said. “We’ve got support for those who have lost loved ones. We’ve got people taking animals in.”

Fire crews were returning from the scene, cold and hungry, LaDouceur said.

“We’ve never had anything like this ever,” she said, “but I have to say how proud I am of everyone here, and all the neighbors we have here, in Snohomish County and in Skagit County.”

Chris Winters: 425-374-4165 or cwinters@heraldnet.com.

Follow us on Twitter for updates as this story develops: @EverettHerald

Donations

The city of Arlington can answer questions about donation needs for victims via administration@arlingtonwa.gov or through the city’s Facebook page.