On January 8, 2005, a 26-year-old male volunteer Fire Fighter (FF) completed Emergency Medical Technician (EMT) training and returned home. The next morning the FF's wife was awakened by his agonal (gasping) breathing. After being unable to wake him, she notified Emergency Medical System (EMS) who arrived to find the FF unresponsive with no pulse, and no respirations. Cardiopulmonary resuscitation (CPR) was begun and a cardiac monitor showed the FF was in ventricular fibrillation (VF). He was shocked (defibrillated) multiple times followed by advanced life support (ALS) medications until his rhythm changed to pulseless electrical activity. During transport to the local hospital, the FF received an external pacemaker and further ALS measures. Approximately 55 minutes later, despite CPR and ALS administered on the scene, in the ambulance, and at the hospital, the FF died. The autopsy revealed mitral valve prolapse with cardiomegaly. The death certificate, completed by the county medical examiner, listed mitral valve failure as the cause of death. It is unlikely the following recommendations could have prevented the FF's death. Nonetheless, the NIOSH investigators offer these recommendations to reduce the risk of on-the-job heart attacks and sudden cardiac arrest among fire fighters: 1. Provide mandatory pre-placement and annual medical evaluations to ALL fire fighters consistent with NFPA 1582, Standard on Comprehensive Occupational Medical Program for Fire Departments to determine their medical ability to perform duties without presenting a significant risk to the safety and health of themselves or others. 2. Ensure that fire fighters are cleared for duty by a physician knowledgeable about the physical demands of fire fighting, the personal protective equipment used by fire fighters, and the various components of NFPA 1582, Standard on Comprehensive Occupational Medicine Program for Fire Departments. 3. Provide fire fighters with medical clearance to wear self-contained breathing apparatus (SCBA). 4. Phase in a mandatory wellness/fitness program for fire fighters to reduce risk factors for cardiovascular disease and improve cardiovascular capacity. 5. Perform an annual physical performance (physical ability) evaluation to ensure fire fighters are physically capable of performing the essential job tasks of structural fire fighting.