Update:  Once again, we see an example of the gap between knowledge known by at least the scientific community about a hazard and the working knowledge of the current public officials. We saw that gap during Hurricane Katrina and we saw it again with Hurricane Sandy, to name just a couple of recent examples.

Apparently, there were several studies and several precedents for landslides in the area of Oso Washington.  The articles below go from oldest to newest:

(1) From the National Geographic: Mudslides Explained: Behind the Washington State Disaster. It begins:

A fatal mudslide in rural northwestern Washington State over the weekend underscores the dangers of this fast-moving natural hazard. On Saturday morning, a mudslide moved down the Stillaguamish River near the small former fishing village of Oso, Washington. Authorities have confirmed eight dead, eight injured, and as many as 108 people missing or unaccounted for as of Monday morning. The one-square-mile (2.6-square-kilometer) track of the mudslide also destroyed about 30 homes.

(2) From the Christian Science Monitor:  Can mudslides be predicted? Washington site’s history highlights challenge. (+video)

Eight people died in the Washington mudslide, and the toll is expected to rise. No detailed hazard map exists for the country as a whole, and no national database exists of past slides and the conditions that caused them.

(3) From the Washington Post, March 30 : Before the Landslides; Warnings about the Unthinkable.  One quote: ” It was a nightmare waiting to happen.”

(4) April 5, Christian Science Monitor: Authorities Knew of Mudslide Danger But Didn’t Tell Residents.