John Ryan / KUOW

An independent commission will delve into the deadliest landslide in Washington history. The commission will seek statewide lessons from the Oso landslide, land use in the Oso area before the slide and the emergency response in the days and weeks afterward.

SEATTLE -- Scientists have concluded that rain, groundwater seepage and a long history of big landslides likely contributed to the massive landslide of March 22 that killed 43 people and destroyed dozens of homes near Oso, Washington.

Those findings came out Tuesday, the result of a scientific team's rapid-fire assessment of geology and localized factors.

Joe Wartman, a University of Washington associate professor of civil and environmental engineering and a co-lead author of the study, said rainfall very likely played a key role in the slide.

Scientists Draw Lessons From Oso Landslide

Jul 22, 2014
The site of the deadly Oso, Washington mudslide on March 22, 2014.
Flickr Photo/Washington State DNR (CC-BY-NC-ND)

Ross Reynolds talks with David Montgomery, professor of geomorphology at the University of Washington, who was part of a team of scientists studying the aftermath of the Oso mudslide in order to help other communities prepare for future disasters.

Flickr Photo/WSDOT (CC-BY-NC-ND)

Lisa Brooks speaks with Snohomish County Council Chair Dave Somers about a temporary ban on development in two landslide-prone areas near the site of the Oso, Wash., landslide that killed 43 people in March.

How to keep a county that is still reeling from a deadly landslide safe from future landslides?

Environmentalists' and developers' conflicting answers to that question will get a full airing on Wednesday at the Snohomish County Council in Everett. The council is holding a special hearing on ways to reduce the chances of new homes being put in where landslides might take them out.

The Timberbowl Rodeo, in the town of Darrington, Washington, saw some of its largest crowds ever this past weekend. Neighbors gathered at the event to hug, shake hands and heal up a bit from this year's nearby terrible Oso landslide.

The deadly Oso landslide in March has resulted in a blizzard of legal claims against the state of Washington.

Flickr Photo/WSDOT (CC-BY-NC-ND)

Ross Reynolds speaks with Martha Rasmussen, organizer of Darrington Day, about the fortuitous connection between the re-opening of state Route 530 and the annual celebration of Darrington Day. Both events take place Saturday May 31.

KUOW Photo/Ashley Ahearn

Barbara Ingram furrows her brow as she peers into a patch of woods up the road from her house. Developers have had their eyes on this place, too.

Amid Grief, Darrington Students Dress Up And Head To Prom

May 20, 2014
Courtesy of Taylor Lindeman

Taylor Lindeman and her boyfriend Anthony Smith drink Red Bull, waiting to get their hair done. Taylor will get a waterfall braid. Anthony wants a haircut, but he’s resisting Taylor’s efforts to have his red bushy beard trimmed. He keeps telling people he wants to grow it out and go “mountain man.”

Washington Department of Natural Resources

Washington State officials announced new restrictions on logging near landslide zones Friday afternoon.

The change in policy comes six weeks after a landslide near the town of Oso killed at least 41 people.

KUOW Photo/Daniel Berman

Aid agencies are reducing their presence in Oso and Darrington, a month and a half after a landslide hit the small community there, killing at least 41.

King County

King County is seeking federal funding for an updated map of landslide hazards, and is considering the possibility of using this map to provide the public information about buildings at risk.

How Drones Quietly Mapped Oso Landslide Area

May 5, 2014
Tamara Palmer

As Washington Gov. Jay Inslee vetoed a bill in April that would have regulated drone use statewide, a consortium of disaster recovery specialists quietly negotiated the use of drones to make a 3-D model of the Oso mudslide.

Inslee vetoed the Legislature's bill on April 4 citing privacy and transparency concerns that he said were not adequately addressed, but he said he would still let drones fly in emergencies.

KUOW Photo/Ashley Ahearn

The Oso mudslide drew hundreds of volunteers to the towns of Arlington and Darrington, Wash.

Mixed in among those responders were 50 young people in the Washington Conservation Corps between the ages of 18 and 25.