Body Of Last Oso Mudslide Victim Believed Found, Rainfall Played Big Role

Everett, WA — The body of the final Oso mudslide victim is believed to have been found, according to the Snohomish County sheriff’s office. Search and rescue personnel believe they located the body of 44-year-old Molly Kristine “Kris” Regelbrugge. However, the woman’s family is remaining cautious after several false alarms.

Sara Regelbrugge, Kris’ daughter, told King-5 News that her family got the call Tuesday morning. However, the family has been told more than 10 times since the slide on March 22 that searchers may have found her mom, only to learn it was partial remains of another victim.

Sara added that they could learn as early as Tuesday night whether the remains are actually Kris. The 44-year-old woman and her husband, Navy Cmdr. John Regelbrugge III, were killed in the slide along with 41 other residents. John’s body was one of the 42 recovered earlier, but the initial search for victims ended in April.

However, workers have been screening debris and watching for Regelbrugge. The news of the final victim’s potential recovery comes the same day a report was released by a team of scientists and engineers trying to discover the cause of the devastating Oso mudslide.

The Seattle Times reports that the massive landslide north of Seattle likely unfolded in two phases, with the first one causing the most damage and loss of life.

The lower portion of the slope, including a mass of soil and rock leftover from a previous slide in 2006, gave way first. As the saturated soil gained momentum, it became more fluid, plowing across the Stillaguamish River, picking up more water. It then flowed over the Steelhead Haven Drive neighborhood, killing 43.

Destabilized by the initial slide, the upper portion of the hill then collapsed, slumping and dropping down several hundred feet. However, that portion did not travel far enough to add significantly to the devastation.

The authors have not been able to pinpoint what triggered the slide, though several factors include extreme rainfall and changes in groundwater flow due to previous slides and logging. The authors wrote, “Our investigation is not intended to be a final, conclusive study of the landslide and we did not seek to unequivocally establish causative factors.”

The scientists stress that they were not able to reach any definitive conclusions on what happened. Carbon dating of an ancient landslide scarp also showed that the hillside where the Oso mudslide took place has been sliding for at least 6,000 years. The team estimated that the North Fork of the Stillaguamish River has been hit with 15 major landslides in the past 6,000 years.

Joseph Wartman, a University of Washington associate professor of civil and environmental engineering and a team leader for the study, added, “Perhaps the most striking finding is that, while the Oso landslide was a rare geologic occurrence, it was not extraordinary.”

The Oso mudslide is the deadliest in United States recorded history with an economic toll of more than $50 million.

[Image by Spc. Samantha Ciaramitaro]