People of Northwest Public Radio
Tue July 22, 2014
Scientists Say Earlier Slide Set Up Oso Disaster
A small landslide in 2006 set the stage for the catastrophe that claimed 43 lives in Oso, Wash. this past March. A panel of scientists says that first slide left a loosely packed mass of debris suspended above the Steelhead Haven development and its neighbors.
Joseph Wartman is a civil and environmental engineer with the University of Washington, and the lead researcher on the federally funded study. He says this year spring rains saturated the unstable ground and let loose a huge slab. Within seconds it liquefied, sending a torrent more than half a mile across the valley floor. Wartman says the length of its destruction isn’t really abnormal, but it’s still kind of shocking.
“You know when we were at the site and you take a look at it, even as someone who’s a trained professional in this area, it’s difficult to imagine that runout could come that far, when you look up to the slope,” Wartman said.
Minutes after that slide, a second, higher mass of earth slipped, filling the bald spot left by the first.
In all, researchers say the slide moved 270 million cubic feet of earth, and was the deadliest in American history.
Just as the team was delivering its findings, word came that the landslide’s final missing victim appears to have been recovered. Search crews believe they found the body of Molly Kristine Regelbrugge. She was 44 years old.
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