This report continues a series of annual studies by the USFA of on duty firefighter fatalities in the United States. The specific objective of this study is to identify all on duty firefighter fatalities that occurred in the United States in 2001 and to analyze 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 2001 overal findings, this study includes assessments of trends over the past 6 years, as well as special analysis on actions that can immediately impact cardiac health and firefighter safety during emergency operations.