On November 5, 2005, a 43-year-old male career Fire Fighter (FF) was engaged in exterior fire fighting operations at a residential structure fire. After fire extinguishment and debriefing, he walked to his engine to retrieve his turnout gear and suddenly collapsed. A nearby crew member witnessed the FF collapse and alerted other crew members. Dispatch was notified and sent an ambulance. Cardiopulmonary resuscitation (CPR) was performed, advanced life support (ALS) treatment was given, and the FF was transported to the local hospital's emergency department (ED). Despite CPR and ALS treatment, the FF died. The death certificate and the autopsy listed "atherosclerotic cardiovascular disease (CVD)" as the cause of death. The NIOSH investigator concluded that the FF's sudden cardiac death was due to his underlying atherosclerotic CVD, possibly triggered by the physical exertion associated with fire fighting duties. NIOSH investigators offer the following recommendations to prevent similar incidents, and to address general safety and health issues: 1. Provide annual medical evaluations consistent with National Fire Protection Association (NFPA) 1582 to ALL firefighters to determine their medical ability to perform duties without presenting a significant risk to the safety and health of themselves or others. 2. Phase in a MANDATORY wellness/fitness program for fire fighters to reduce risk factors for cardiovascular disease and improve cardiovascular capacity. 3. 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. 4. Institute incident scene rehabilitation (rehab) during working structural fires. 5. Provide a transport ambulance at the scene of working structural fires. 6. Discontinue lumbar spine x-rays as a screening test administered during the pre-placement medical evaluation.