Why the U.S. Lacks a National Landslide Warning System

When the massive debris flow of trees, rocks and mud swiftly buried the Steelhead Drive Development in Oso, Wash., on Saturday morning, killing at least 14, it did so without any warning. With at least 176 people still listed as missing since the landslide hit, this could be the second-deadliest landslide in U.S. history.

According to the U.S. Geological Survey (USGS), landslides in the U.S. typically cause between $1 billion and $2 billion worth of damage, and kill more than 25 people each year. They happen in all 50 U.S. states plus its territories, and can take many forms.