On the morning of November 21, 2007, a 48-year-old male career Senior Fire Fighter (FF) and his crew responded to two calls: a carbon monoxide alarm and a reported residential kitchen fire. The carbon monoxide call ended without any evidence of carbon monoxide exposure. The reported kitchen fire was eventful for icy road conditions which resulted in a near crash of the apparatus. The response was cancelled and after the crew returned to their fire station, the FF suddenly collapsed with seizure-like activity. Crew members found him unresponsive, with agonal (gasping) breathing, and without a pulse. Crew members began cardiopulmonary resuscitation (CPR) and advanced life support treatment as the station's ambulance transported him to the local hospital's emergency department. Approximately 40 minutes later, despite CPR and advanced life support administered on-scene and at the hospital, the FF died. The death certificate, completed by the local county coroner's office listed "mitral valve redundancy" as the cause of death. The autopsy was performed by the forensic pathologist at a neighboring coroner's office who concluded the FF "expired as a consequence of an arrhythmic event related to a defective mitral valve." The NIOSH investigator agrees with this conclusion, and that the emergency response may have triggered the FF's cardiac arrhythmia. The following recommendations address general safety and health issues. Had these recommendations been in place prior to the FF's collapse, perhaps his sudden cardiac death could have been prevented at this time. 1. Provide mandatory annual medical evaluations to fire fighters consistent with National Fire Protection Association (NFPA) 1582 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 firefighting. 3. Incorporate exercise stress tests following standard medical guidelines into the Fire Department's medical evaluation program. 4. Provide fire fighters with medical clearance to wear self-contained breathing apparatus (SCBA) as part of the Fire Department's medical evaluation program. 5. Phase-in a comprehensive wellness and fitness program for fire fighters to reduce risk factors for cardiovascular disease and improve cardiovascular capacity. 6. Perform an annual physical performance (physical ability) evaluation to ensure fire fighters are capable of performing the essential job tasks of structural firefighting. 7. Review procedures for maintaining batteries in cardiac monitors.