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ARLINGTON, Wash. – A scientist working for the government had warned 15 years ago about the potential for a catastrophic landslide in the village where the collapse of a rain-soaked hillside over the weekend killed at least 16 people and left scores missing.

Washington state officials said Tuesday evening searchers had recovered two bodies and believe they’ve located another eight in the debris of the massive landslide. The grim discoveries put the official death toll at 16, with the possibility of 24 dead once the other bodies are confirmed.

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 slogged through the muck and rain in search of victims Tuesday, word of the 1999 report raised questions about why residents were allowed to build homes on the hill and whether officials had taken proper precautions.

“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 U.S. Army Corps of Engineers to do the study. “I was not surprised.”

Snohomish County officials and authorities in the devastated fishing village of 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 were issued immediately 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.

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, and this particular river valley has had three very large slides in the last three decades.

Predicting landslides is difficult, according to a study published by the U.S. Geological Survey in 2012. One challenge is estimating the probability of a slide in any particular place.

One of the authors of the USGS report, Jonathan Godt, a research scientist in Colorado, said landslides don’t get that much attention because they often happen in places where they don’t hit anything. But with Americans building homes deeper into the wilderness, he said, “there are more people in the way.”