A wide aerial view shows a huge volume of earth missing from the side of a hill facing the Stillaguamish River, in a landslide along State Route 530, between the cities of Arlington and Darrington, on Saturday, March 22, 2014
After hearing voices pleading for help, rescuers searched overnight for survivors from a massive mudslide in Washington state that killed at least three people and forced evacuations because of fears of severe flooding.
The slide of mud, trees and rocks happened about 11 am on Saturday. Several people - including an infant - were critically injured and at least six houses were destroyed.
Snohomish County Fire District 21 Chief Travis Hots said at a news briefing late on Saturday that searchers weren't giving up on finding more people alive.
"We have people who are yelling for our help, and we are going to take extreme risks," Hots said.
It wasn't clear how many people might still be trapped - or if more bodies might be discovered.
"This is still a rescue mission until we determine otherwise," Hots said. "We don't have a firm idea of how many people are out there."
Shari Ireton, spokesperson for the Snohomish County Sheriff's office, said rescuers were using thermal imaging cameras to help try to find people.
The slide blocked the North Fork of the Stillaguamish River, which prompted an evacuation notice because water was rising rapidly behind the debris. Authorities worried about severe downstream flooding if water suddenly broke through the blockage.
The landslide also completely covered State Route 530 near the town of Oso, about 55 miles (90 kilometers) north of Seattle. It was at least 135 feet (41 meters) wide and 180 feet (55 meters) deep, Snohomish County authorities said.
The Snohomish County sheriff's office reported that two people had been killed at the scene. Authorities later said one of the people who was rescued died at a hospital.
The injured included a 6-month-old boy, who was in critical condition at Harborview Medical Center in Seattle. Hospital spokeswoman Susan Gregg said two other victims were in critical condition - an 81-year-old man and a 37-year-old man - while a 58-year-old man and a 25-year-old woman were in serious condition.
Five of the injured were brought to Cascade Valley Hospital in Arlington, and one has already been treated and released, said hospital spokeswoman Jennifer Egger. She didn't know the condition of the others.
The American Red Cross set up at the hospital, and evacuation shelters were set up at a nearby school and elsewhere.
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.
Hots said crews heard voices late Saturday night on the eastern edge of the debris field. Snohomish County Sheriff Ty Trenary said "we have rescuers on the ground on both sides of the slide who are going to be there all night, we're combing through the debris field on the ground trying to rescue people."
Iretonsaid the number of destroyed homes was expected to increase when crews had more time to assess the scene.
The National Weather Service issued a flash flood watch for Snohomish County through Sunday afternoon.
Washington Gov. Jay Inslee proclaimed a state of emergency.
Authorities believe the slide was caused by ground water saturation from recent heavy rainfall. John Pennington from the Snohomish County Department of Emergency Management said the area has a history of unstable land. He said a slide also happened there in 2006.