EVERETT — After a barrage of damage claims, the first lawsuit has been filed against Snohomish County and the state by families who lost loved ones in the March 22 Oso mudslide.

The lawsuit, filed Tuesday in King County Superior Court, claims the county and state Department of Natural Resources were negligent and caused the deaths of two Oso families who were related.

It was filed in behalf of the estates of Lewis and JuDee Vanderburg, 71 and 64, and Shane and Katie Ruthven, 43 and 34, as well as their children, Hunter and Wyatt, 6 and 4. Hunter was in kindergarten at Kent Prairie Elementary School in Arlington and Wyatt was in pre-school.

They were among the 43 people who were reported missing after the slide. All but one of the mudslide’s victims have been recovered.

The lawsuit, filed by Seattle attorneys Guy Michelson and Emily Harris, took particular exception to statements made by Snohomish County officials immediately after the disaster, maintaining the slide “came out of nowhere” and that a slide “of this magnitude is very difficult to predict.”

County officials knew from numerous studies and previous geologic activity in the area known as the Hazel Landslide that there “was an active deep-seated landslide that posed a significant risk of catastrophic failure, placing human life at risk,” they said in court papers.

They added: “… Public safety should have been defendant’s number one priority. Unfortunately, it wasn’t.”

The lawsuit contends that homes were built starting in the 1960s without a flood control permit and that later families were given little information about the threats of a potential run-out zone of the Hazel Landslide.

There were major slides on the hill in 1967 and 2006.

People living in the neighborhood were led to believe that the safety risk had been addressed by construction of a wooden retention wall in 2006 along the edge of the North Fork Stillaguamish River at the base of the Hazel Slide, according to allegations made in the lawsuit.

The complaint also blamed forestry practices in the area, pointing to a recommendation in a 1988 state report “that no timber harvest take place in the areas responsible for supplying groundwater to the Hazel Slide now or in the future” because it could reduce stability of the land.

The lawyers also cited a 2000 study by the U.S. Army Corps of Engineers that suggested the slide could cut loose in a catastrophic fashion, placing “human lives and properties at risk.”

Although dozens of damage claims have been filed against the county in connection with the mudslide, this is the first to have resulted in a lawsuit, said Jason Cummings, the county’s chief civil deputy prosecutor. Damage claims typically precede lawsuits.

He declined comment, saying his office had yet to review the lawsuit, which does not specify damages sought.

The attorneys filed paperwork April 29 suggesting a jury likely would award “several million dollars” to the plaintiffs if the case went to trial.

More lawsuits are coming. Seattle attorney Corrie J. Yackulic and her co-counsel represent families of 13 people who died in the slide as well as another six families and others who lost property. They expect to file a lawsuit soon for their clients, and are now studying how a variety of factors — including logging and attempts to engineer the river bank — likely figured into the slide.

“We are combing through tens of thousands of documents produced by the county, the state, and other agencies, and are reviewing historic data and records available through other sources,” Yackulic said. “We are working with scientists with expertise in different fields — hydrology, geomorphology, engineering geology, river morphology — to understand the ways in which human activity … turned a natural hazard into a disaster with extensive loss of human life and property.”

The Ruthvens moved into the Steelhead Haven neighborhood in late 2006 and wed a few months later. Their house had been there since 1975.

The couple owned and operated Mountain Lion Glass, a company they founded to replace windows in buildings and condos. The Vandenburgs had moved from Spokane to live near their grandsons. He was a retired corrections officer; she had worked in retail.

Katie Ruthven was the daughter of former Snohomish County sheriff’s Sgt. Tom Pszonka, who in the days immediately after the mudslide recounted how happy the family had been living near Oso.

Eric Stevick: 425-339-3446, stevick@heraldnet.com