Three people are known to have died, and several more are in critical conditions, following a landslide near the town of Oso in Snohomish County in Washington State, about 55 km north of Seattle, that occurred slightly before 11.00 am local time on Saturday 22 March 2014. The landslide completely blocked State Route 530 as well as destroying six houses and blocking the North Fork of the Stillaguamish River, prompting an evacuation of nearby communities at risk of flooding. Those recieving hospital treatment for critical injuries are known to include an 81-year-old-man, a 58-year-old-man and a six-month-old boy. Rescuers are still searching for more people at the site of the event.
The aftermath of the 22 March 2014 Snohomish County landslide. Marcus Yam.
The landslide was over 40 m wide and 50 m deep. It is thought to have been caused by heavy rainfall which lead to the ground becoming waterlogged. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.
The approximate location of the 22 March 2014 Snohomish County landslide. Google Maps.
See also Two killed by Utah rockfall, Five killed by Colorado rockfall, Five confirmed dead in Colorado flooding, and over 600 still missing, Arizona man injured in rockfall on Mount Elden, north of Flagstaff and Magnitude 3.0 Earthquake in Washington State.
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