A major mudslide devastated an area four miles east of Oso, Wash. when part of a hillside collapsed early morning Saturday, March 22. The mudslide was reported to have reached one square-mile, destroying everything in its path. More than 30 homes were demolished by the slide as the mud and debris blocked a one-mile stretch of state highway Route 530.
The main explanation for the sudden tragedy is an excess of rain in the past several weeks. Although it was not raining on Saturday when the mudslide occurred, experts say this is the primary reason a 1,500 foot-wide segment of hillside in Snohomish County was cut away.
“That soil tends to be loose, which has allowed rivers – like the Stillaguamish River along the mudslide site – to carve out valleys and steep hillsides,” said David Montgomery, a geologist at the University of Washington. He further explains that hillsides often give way when they become overly saturated by rainwater, and are affected by pressure and gravity.
According to the Los Angeles Times, the hillside that cut away Saturday had experienced previous mudslides in the 1960s and in 2006. Unfortunately, it is nearly impossible to predict when and how the mudslides will occur.
“It’s not certain places at certain times. But we don’t really know why that is,” said Brent Bower, a National Weather Service hydrologist. “We’ve had storms that produce thousands [of mudslides] in one storm, but we can’t be real precise about the location and the timing.”
Since Saturday, rescue teams have been sent to Snohomish County in an attempt to save those lost in the debris or at least bring consolation to family members by discovering bodies. The teams have searched for any signs of life, but with the rising death toll, many residents of Snohomish have lost hope.
The debris field was roughly one square mile, and 30 to 40 feet deep in places. It also has a surface that includes quicksand-like muck, rain-slickened mud and ice. The area includes fallen trees, septic tanks and shards from destroyed homes. The terrain is still difficult to navigate on foot and makes it nearly impossible for rescue teams to bring in the heavy equipment they need to dig people out of the mud.
Snohomish County Fire Chief Travis Hots hailed the rescue crews on Thursday, March 27 as “unsung heroes,” saying that one crew skipped a lunch break to continue searching for bodies.
Despite all the assistance that residents are receiving, some locals were angry with officials who refused to allow residents access to the mudslide site immediately after the incident. Many complained that it was their right to be able to help with the rescues. Authorities kept the area sealed off in an attempt to keep out the residents. However, on Tuesday, they finally allowed volunteers to enter.
President Barack Obama signed an emergency declaration Monday ordering government assistance in relief efforts. The relief account had nearly $50,000 by Thursday.
Snohomish County Emergency Management Director John Pennington said Wednesday the biggest day-to-day change was in the number of people confirmed missing. As of Monday, March 31, the number of unaccounted people remained at 30. Rescue crews confirm that at least 18 people have died as a result of the mudslide.
Due to the lack of any new leads or rescues, Governor Jay Inslee said Wednesday, March 26 the only conclusion he can make is that the death toll will rise significantly in the next few days.
Editor’s Note: Information from CNN, the Los Angeles Times and The New York Times was used in this report.