Drought conditions in the United States in recent years bring increased attention to the age-old issue of power line-caused fires. It has long been known that power line faults and failures can cause wildfires through multiple mechanisms. Failure mechanisms of various apparatus and operational conditions that result in wildfire ignition are reviewed. Case studies of faults and failures from operating utility systems are presented, along with a discussion of how these faults and failures represent competent sources of ignition for wildfires. Methods of preventing power line-caused wildfires are discussed. © 2012 IEEE.