On December 1, 2006, a 44-year-old male career Fire Fighter (FF) was participating in physical fitness training in preparation for the Fire Department's annual physical fitness examination and the job-related physical agility test (JRPAT). After running (sprinting) for about 15 minutes he collapsed. A passerby alerted the fire fighters in the fire station. Crew members found the FF unresponsive, not breathing, and without a pulse (1748 hours). Dispatch was notified, cardiopulmonary resuscitation (CPR) and advanced life support were begun, and the FF was transported to the hospital's Emergency Department. Inside the Emergency Department, advanced life support treatment continued with no improvement in the FF's condition. The attending physician pronounced the FF dead at 1819 hours and resuscitation efforts were discontinued. The death certificate and autopsy (completed by the Medical Examiner) listed "hypertrophic obstructive cardiomyopathy" as the cause of death. NIOSH investigators offer the following recommendations to address general safety and health issues. However, it is unclear if any of these recommendations could have prevented the FF's sudden death. 1. Perform periodic medical evaluations consistent with National Fire Protection Association (NFPA) 1582, Standard on Comprehensive Occupational Medical Program for Fire Departments. The Fire Department and Union should negotiate the content and frequency of the evaluations to be consistent with NFPA 1582. 2. Fire fighters should be medically cleared prior to participating in the Fire Department's physical fitness examination and the job-related physical agility test, specifically, by taking the aerobic capacity (treadmill) test. 3. Provide fire fighters with medical evaluations and clearance to wear self-contained breathing apparatus (SCBAs).