SEATTLE -- A decade before a landslide buried a Washington community, county officials considered buying up people's homes there to protect them from such a disaster.

A 2004 Snohomish County flood-management plan said the cost of purchasing properties in Oso "would be significant, but would remove the risk to human life and structures."

But documents show after weighing options, the county instead recommended a project to stabilize the base of a nearby unstable slope.

It built a 1,300-foot-long wall to reduce landslide and flood risks. But that wasn't enough to hold back the square mile of dirt, sand and silt that barreled down the mountain March 22, killing at least 30 people.

Some area residents and their family members say they knew nothing of the landslide dangers or home-buyout proposals.

The documents were reported by The Seattle Times.

As medical examiners piece together the identities and lives of the people known killed in the mudslide, one mystery troubles them.

One set of remains does not fit with the description on the missing persons list, which, as of Wednesday included 18 people.

The medical examiners know it is a male. But his remains give no clue as to who he was or who might be looking for him. They can't identify his age range. Without possible family members to compare, DNA tests are useless. At this point, gold teeth are all they have to go on.

The mystery underscores the tedious identification of remains more than a week after the landslide broke off a steep hill, roared across the North Fork of the Stillaguamish River and buried Oso.

Like the homes, cars and the other parts of people's lives swept away by the mud, some bodies are in pieces.

Norman Thiersch, the Snohomish County Medical Examiner, said the goal of the team of medical examiners, detectives, dentists and others is to ensure there's no doubt as to the identities of the victims.