ARLINGTON, Wash. — Washington state officials said Tuesday that searchers found two more bodies in the debris of a massive landslide, raising the number of people who died in the disaster to at least 16.
Snohomish County District 21 Fire Chief Travis Hots announced the fatalities after residents from the nearby logging town of Darrington spent the day helping rescue crews scour the muck for any sign of survivors.
The grim discoveries came three days after the collapse of a rain-soaked hillside about 55 miles north of Seattle.
Searchers had warned they were likely to find more bodies in the debris field, which covered a neighborhood of 49 structures. Authorities believe at least 25 were full-time residences.
They were working off a list of 176 people unaccounted for, though some names were believed to be duplicates.
As rescue workers searched for victims, word of a 1999 report raised questions about why residents were allowed to build homes on the hill and whether officials had taken proper precautions.
A scientist working for the government warned 15 years ago about the potential for a catastrophic landslide in the village of Oso.
“I knew it would fail catastrophically in a large-magnitude event,” though not when it would happen, said Daniel Miller, a geomorphologist who was hired by the US Army Corps of Engineers to do the study. “I was not surprised.”
Snohomish County officials and authorities in Oso said that they were not aware of the study.
But John Pennington, director of the county Emergency Department, said local authorities were vigilant about warning the public of landslide dangers, and homeowners “were very aware of the slide potential.”
In fact, the area has long been known as the “Hazel Landslide” because of landslides over the past half-century. The last major one before Saturday’s disaster was in 2006.
“We’ve done everything we could to protect them,” Pennington said.
Patricia Graesser, a spokeswoman for the Army Corps of Engineers in Seattle, said it appears that the report was intended not as a risk assessment, but as a feasibility study for ecosystem restoration.
Asked whether the agency should have done anything with the information, she said: “We don’t have jurisdiction to do anything. We don’t do zoning. That’s a local responsibility.”
No landslide warnings for the area were issued before the disaster, which came after weeks of heavy rain. The rushing wall of quicksand-like mud, trees, and other debris flattened about two dozen homes and critically injured several people.
“One of the things this tragedy should teach us is the need to get better information about geologic hazards out to the general public,” said David Montgomery, a geomorphologist and professor with the University of Washington in Seattle.
“Where are the potentially unstable slopes? How big a risk do they pose? And what should be done to let homeowners know about that?”
The threat of flash floods or another landslide loomed over the rescuers on Tuesday.
Near the southern perimeter of the slide, volunteers from a logging crew gathered to help move debris with chainsaws, excavators, and other heavy equipment.
Gene Karger said he could see six orange flags in the debris field, marking bodies they would be pulling out. Karger, a logger most of his life, said it was the first time he was involved in this kind of rescue work.
“You see parts of their bodies sticking out of the mud. It’s real hard. It’s that bad,” Karger said. “There are people out there we know.”
In his report, Miller said that the soil on the steep slope lacked any binding agent that would make it more secure, and that the underlying layers of silt and sand could give way in a “large catastrophic failure.”
But he also cautioned: “I currently have no basis for estimating the probable rate or timing of future landslide activity.”
In an interview Tuesday, Miller noted there are hundreds of similar landslides in Washington state each year.
Predicting landslides is difficult, according to a study published by the US Geological Survey in 2012. One challenge is estimating the probability of a slide in any particular place.