The consistency of debris flows range from thin or thick mud to rocky mud that can forcefully carry larger items of destruction such as boulders, trees, and cars.
When flows reach flatter ground, the debris spreads over a broad area, and can accumulate in thick deposits that wreak havoc in developed areas.
Every year, landslides in the U.S. cause roughly $3.5 billion in damage and kill between 25 and 50 people.
