My brother in law was there the day it happened and noted a dozen or so dirt bikes riding up and down the BNSF fire breaks even during the fire fight. Dirt bikes are really good at starting fires too. I've been in the area numerous timed both before and since, people around there make no effort to protect themselves by removing dead snags, excessive needle build up, and creating a defendable space and the Department of Natural Resources (the people who end up fighting the fires and helped fight this one) has TOLD THEM TO DO many times in recent years. The fire Spokane Valley had a couple of weeks ago proved defendable spaces do work as the fire bypassed several homes that had taken the time to maintain their space. Too many people that live in the woods don't want to do the work required to protect themselves, or are afraid to disrupt nature. And yes, those skinny overgrown trees are pretty much worthless, skinny, overcrowded, some partly fallen over (to better carry the fire from the floor to the crown).
Getting rid of their cedar shake roofs would help themselves too.