BEND, OR -- Chimney fires are caused by a build-up of creosote. They are less common than they once were according to Bend Battalion Fire Chief David Howe because many people have switched to other sources of heating fuel like electricity or natural gas. But for those burning wood products, Howe says, getting the chimney flu inspected and cleaned is important because, "If you burn fuel that is fairly wet and hasn't been seasoned a long time, you are more likely to build up more creosote. And if you burn fuel fairly cool, like a smoldering fire, that's gonna build up creosote really fast." Howe says get the chimney inspected and cleaned twice a year if your fuel is increasing the creosote build up in the chimney.