This report continues a series of annual studies by the USFA of onduty firefighter fatalities in the United States. The USFA is the single public agency source of information for all onduty firefighter fatalities in the United States each year. The unique and specific objective of this study is to identify all onduty firefighter fatalities that occurred in the United States and its protectorates in 1999, and to present in summary form the circumstances surrounding each occurrence. The study is intended to help identify approaches that could reduce the number of firefighter deaths in future years. In addition to the 1999 overall findings, this study includes special analyses on vehicle collisions and personal protective clothing and equipment use.