What disaster hazard has killed the most people in Washington state?
If I were asked the question "cold" I would likely say flooding is the deadliest disaster hazard, since people in Washington state routinely drive around "Road Closed" signs and end up drowning. But no, in Washington state it is avalanches that have killed the most people.
This is a national number, as reported on NBC News today: Avalanches Kill 15 in One Week
Note that the majority of these deaths come from backcountry skiing and snowmobiling. Risky behavior to be sure!