On July 4, 2006, a 35-year-old male volunteer Fire Fighter (FF) responded to a rescue call for rafters (boaters) who had fallen into a river at approximately 1431 hours. Once on scene, the FF stood by the apparatus while the rafters were rescued upstream and the emergency was declared under control. Units returned to their station, the equipment was readied for the next call, and the FF returned home for the evening. The next morning, July 5th, the FF went to his regular job at a local manufacturing plant. After visiting the infirmary for a skin rash, he went to his work station and suddenly collapsed. Coworkers, including the plant's medical emergency response team responded, called 9-1-1, and began medical treatment including cardiopulmonary resuscitation (CPR). Ambulance personnel began advanced life support treatment and transported the FF to the hospital's emergency department. Despite advanced life support and CPR, the FF died. The death certificate and autopsy (completed by the forensic pathologist) listed "mitral valve prolapse" as the cause of death. The NIOSH investigator concluded that the FF's underlying mitral valve prolapse and/or left ventricular hypertrophy were responsible for his sudden cardiac death, possibly triggered by the physical stress of responding to the rescue call. NIOSH investigators offer the following recommendations to address general safety and health issues. It is doubtful any of these recommendations would have prevented this FF's sudden cardiac death. 1. Perform pre-placement and periodic medical evaluations consistent with National Fire Protection Association ( NFPA) 1582 , Standard on Comprehensive Occupational Medical Program for Fire Departments. 2. Secure endotracheal tubes to prevent dislodgment during patient treatment, transfer, and transport. 3. Ensure that fire fighters are cleared for duty by a physician knowledgeable about the physical demands of firefighting, the personal protective equipment used by fire fighters, and the various components of NFPA 1582. 4. Provide fire fighters with medical evaluations and clearance to wear self-contained breathing apparatus (SCBAs). 5. Develop a structured wellness/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 physically capable of performing the essential job tasks of structural firefighting.