Washington Mudslide

At approximately 1:45 p.m. on Saturday, March 22, 2014, a major landslide occurred 4 miles east of Oso, Wash. (and 17 miles east of Arlington, Wash.), in OSHA Region X when a portion of a hillside collapsed. Mud and debris from engulfed residential sites slid across the North Fork area of the Stillaguamish River in Snohomish County.

The area where the mudslide occurred experienced up to 200 percent normal rainfall during the previous 45 days. Nearby Arlington, Washington reported 7.33 inches of rain that month, almost double the average for March and the area's fourth-wettest March on record.


The mud, soil and rock debris left from the mudslide is 1,500 ft. (460 m) long, 4,400 ft. (1,300 m) wide and deposited debris 20 to 40 ft. (9.1 to 12.2 m) deep. The mudslide area is about 1 sq. mi.

The slide blocked the North Fork of the Stillaguamish River which backed up eastward toward the nearby town of Darrington. By that evening, officials were concerned that the mud and debris dam could fail, causing downstream flooding. On March 23, 2014, the river began flowing through a hole in the debris dam. As of March 25, 2014, a flash flood watch issued by the National Weather Service remained in effect. However, the river was flowing around the north end of the debris dam and the likelihood of a flash flood is very low. Highway 530 was closed indefinitely and an alternative route around the slide was being prepared by the Washington State Department of Transportation.

Late in the evening of March 22, 2014, Washington Lieutenant Governor Brad Owen declared a state of emergency in Snohomish County. A Stafford Act declaration for the incident went into effect as of March 24, 2014. The Department of Homeland Security (DHS), Federal Emergency Management Agency (FEMA), is authorized to provide appropriate assistance within Snohomoish County for required emergency measures, authorized under Title V of the Stafford Act, to save lives and to protect property and public health and safety, or to lessen or avert the threat of a catastrophe in the designated areas. Specifically, FEMA is authorized to provide emergency protective measures (Category B), limited to direct federal assistance, under the Public Assistance program at 75 percent federal funding.

OSHA Region X and staff from the Bellevue Area Office reached out to the Incident Command (IC) on Monday, March 23, 2014. The IC requested OSHA assistance with developing a safety plan and to provide training for volunteers. The Directorate of Technical Support and Emergency Management (DTSEM) in the National Office worked with the Office of Communications and the National Institute for Environmental Health and Safety to make safety and health quick cards, booklets, and other guidance materials available to response and recovery workers and volunteers on scene, as well as to homeowners in the impacted area.


OSHA Region X, Bellevue Area Office, and DTSEM worked with the IC, the state occupational safety and health program (OSHA State Plan / Washington Division of Occupational Safety and Health [DOSH]), and other stakeholders to provide resources for responder training and protection.

Transition to Recovery

As of April 2, 2014, federal OSHA transitioned out as an active participant in the IC at the site. DOSH Consultation integrated into the IC, and the IC team maintained regular contact with the DOSH consultation manager. The DOSH consultation manager coordinated state consultative services and worked with federal, state and local agencies (including EPA, Washington Department of Ecology, and FEMA). The site safety team consisted of an IC Safety Officer from the U.S. Forest Service (USFS), a FEMA Safety Officer, Two Army National Guard Safety Officers, and additional state and local safety officers for a total of 16.

The FEMA National Incident Management Assistance Team-West and a FEMA Urban Search and Rescue Incident Support Team remained on scene. FEMA Region X Incident Management Assistance Team and Mobile Emergency Response Support equipment remained deployed. The total number of federal employees onsite was fluid; changing as more assets mobilized and others demobilized.

The Bellevue Area Director (AD) continued to act as a liaison between federal OSHA and the USFS-led IC, offering technical assistance as needed, and attending weekly planning or coordinating meetings as well. The Bellevue (AD) met with the IC on Friday, April 4, 2014, to negotiate that role.