A MUDSLIDE which has killed at least 14 people in an area north of the American west coast city of Seattle was so powerful, it tore houses from their foundations and stripped a hillside of forest.
An estimated 176 people are still missing or unaccounted for.
Hundreds of thousands of tonnes of mud swept through a settlement near the town of Oso, in Snohomish County, 55 miles north of Seattle, Washington State.
The mudslide destroyed 30 homes on Saturday, a day of warm sunshine after weeks of rainstorms.
Professor David Montgomery, an earth and space sciences expert at the University of Washington, said the heavy rain caused a “giant slump” of ground covering the forested hillside above properties in which vacationing visitors and villagers were sleeping.
Another scientist who documented the landslide conditions on the same hillside that buckled had previously warned in a 1999 report of “the potential for a large catastrophic failure” .
The report was written by geomorphologist Daniel J Miller and his wife, Lynne Rodgers Miller. “We’ve known it would happen at some point,” Mr Miller said.
Municipal officials insisted on Monday they were not aware of the warnings in the 1999 report, which had been handed over to the United States Army Corps of Engineers.
“A slide of this magnitude is very difficult to predict,” Snohomish public works director Steve Thomsen said. “There was no indication.”
The mudslide shattered birch trees and vehicles, including residents’ pickup trucks. It also blocked a fork of the Stillaguamish river, forcing people living upstream to flee their homes.
Ed Hrivnak, who was co-piloting an aircraft that was first to arrive at the scene, said a lot of the houses were not buried; they had simply been smashed to bits by the force of the mudslide.
“The houses exploded,” he said. He added that cars were crushed into little pieces, their tyres the only signs they had ever been motor vehicles.
He said he saw people so covered in mud that searchers could only spot them by the whites of their waving palms.
His helicopter rescued eight people, including a four-year-old boy, who was up to his knees in concrete-like compressed mud. The mud was so sticky, the rescuers were worried about getting stuck so the helicopter hovered about a foot away instead of landing, and the crew chief tried to pull him out.
“He was suctioned in that mud so much that his trousers came off,” Mr Hrivnak said.
The boy was taken to a hospital and reunited with his mother. Mr Hrivnak said the boy’s father and three siblings are missing.
More rescuers soon arrived, with one team of firefighters who waded chest-deep into the mud having to be rescued in turn. The ground search was suspended overnight on Saturday, with the death toll at three.
On Sunday, another five bodies were found. By Monday, another six were located.
The search for bodies was continuing last night.