On May 27, 2005, a 43-year-old male career Lieutenant (LT) participated in 5 hours of physically demanding fire fighter training. The training included fire fighter survival skills and a self-contained breathing apparatus (SCBA) confidence/endurance drill. After arriving at a fire station, the LT suffered chest pain. Crew members began advanced life support (ALS) treatment and notified dispatch. An ambulance arrived at the station 5 minutes later and found the LT in severe distress due to chest pain and transported the LT to the hospital. As the ambulance arrived at the hospital's emergency department (ED), the LT suffered respiratory and cardiac arrest. Cardiopulmonary resuscitation (CPR) was performed and additional ALS treatment was given. Despite ALS and CPR for over 54 minutes, the LT died. The death certificate and the autopsy, completed by the County Medical Examiner, listed "atherosclerotic cardiovascular disease (CVD)" as the cause of death. The NIOSH investigator concluded that the LT's sudden cardiac death was due to his underlying atherosclerotic CVD, possibly triggered by the physical exertion associated with SCBA training. NIOSH investigators offer the following recommendations to prevent similar incidents, and to address general safety and health issues: 1. Ensure a comprehensive rehabilitation program is in place when operating a physically demanding training exercise. 2. Provide mandatory annual medical evaluations to ALL fire fighters to determine their medical ability to perform duties without presenting a significant risk to the safety and health of themselves or others. 3. Perform periodic exercise stress tests (EST) on members above the age of 45 in accordance with the American Heart Association (AHA) recommendations. 4. Provide fire fighters with medical evaluations and clearance to wear SCBA. 5. Phase in a MANDATORY wellness/fitness program for fire fighters to reduce risk factors for CVD and improve cardiovascular capacity.