Already waging a furious battle against wildfires, heavy-hearted investigators on Thursday will try to figure out what caused a vehicle crash that cost three firefighters their lives in Washington state. The three firefighters, who worked for the U.S. Forest Service, were trying to control a blaze that broke out Wednesday afternoon and spread quickly and erratically, driven by wind and feeding on drought-parched land. They were killed near the tiny town of Twisp, about 30 miles south of the Canadian border, which was quickly evacuated.