Was the Deadly Washington Mudslide Preventable?

Washington Mudslide Before & After — Before-and-after satellite images of the small community of Oso, Wash., which was devastated by a landslide on March 22, 2014. The photo on the left was captured on July 13, 2013, and the photo on the right was snapped on March 31, 2014. (Image credit: DigitalGlobe)

A deadly mudslide that killed at least 29 people when it engulfed the small town of Oso, Wash., in mud and rocks nearly two weeks ago could have been prevented, according to an expert on landslides. Dave Petley, a professor of hazard and risk in the department of geography at Durham University in the United Kingdom, expressed his thoughts in a new post on his blog, The Landslide Blog, which is hosted by the American Geophysical Union (AGU).

"To my mind this was [a] foreseeable event, and as such the disaster represents a failure of hazard management," Petley wrote.

The March 22 landslide occurred when an unstable, waterlogged hillside collapsed on the bank of the Stillaguamish River, which is located approximately 50 miles (80 kilometers) north of Seattle. Satellite images over time reveal the bluff's history of instability, including landslides and erosion within the region in 2001 and 2006, Petley wrote.

"The 2001 landslide left material high on the hillside that was sitting above a scar that was far too steep," he said. "The [remote sensing] data suggests that the runout from such a collapse could be extensive. In that context I find the decision to build new houses at the foot of the landslide to be very surprising."

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Denise Chow was the assistant managing editor at Live Science before moving to NBC News as a science reporter, where she focuses on general science and climate change. Before joining the Live Science team in 2013, she spent two years as a staff writer for Space.com, writing about rocket launches and covering NASA's final three space shuttle missions. A Canadian transplant, Denise has a bachelor's degree from the University of Toronto, and a master's degree in journalism from New York University.