On November 9, 2008, a 42-year-old female volunteer fire fighter trainee participated in an entry-level fire fighter certification class. The training included turnout gear dressing drills, hose maze, self-contained breathing apparatus (SCBA) skill station/low profile, and maneuvering through a maze with no smoke or fire while wearing full turnout gear and SCBA. After completing the hose maze evolution, the Trainee was tired and sweating heavily. After lunch, the Trainee began the maze portion and completed approximately half of the exercise when her SCBA low-air alarm sounded. The Trainee informed the instructor that she wanted to continue. After entering the next portion of the maze and crawling up a slight incline, she did not turn around and back down the decline as required. The Instructor saw that something was wrong and spoke to the Trainee but received no response. At this time, the Trainee's personal alert safety system (PASS) alarm sounded. It took instructors about 10 minutes to remove the Trainee from the maze. Once outside the maze, the Trainee was found to be unresponsive, not breathing, and without a pulse. An ambulance was requested, and cardiopulmonary resuscitation (CPR) was begun. The ambulance arrived about 7 minutes later, and paramedics began advanced life support. One defibrillation was administered without a change in heart rhythm. The Trainee was transported to the hospital's emergency department, where CPR and advanced life support treatment continued. Approximately 59 minutes after her collapse, despite CPR and advanced life support, the Trainee died. The death certificate and the autopsy, completed by the Medical Examiner, listed "arrhythmogenic right ventricular cardiomyopathy/dysplasia" as the cause of death. NIOSH investigators conclude that the physical exertion involved in performing the fire fighter training exercises, coupled with the Trainee's underlying cardiomyopathy/dysplasia and enlarged heart (cardiomegaly), triggered her sudden cardiac death. NIOSH investigators offer the following recommendations to address general safety and health issues. Had these recommended measures been in place prior to the Trainee's collapse, it is possible her sudden cardiac death may have been prevented. 1. Provide preplacement and annual medical evaluations to fire fighters. 2. Incorporate medical monitoring of trainees into rehabilitation programs. 3. Educate fire fighters to report signs and symptoms consistent with a heart attack to appropriate authorities for prompt medical evaluation. 4. Perform a preplacement and an annual physical performance (physical ability) evaluation. 5. Ensure fire fighters are cleared for return to 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. 6. Phase in a comprehensive wellness and fitness program for fire fighters. 7. Provide fire fighters with medical clearance to wear a self-contained breathing apparatus (SCBA) as part of the Fire Department's medical evaluation program. 8. Ensure that all SCBA training is conducted in accordance with NFPA 1404, Standard for Fire Service Respiratory Protection Training. 9. Ensure that training maze props or trailers used in SCBA confidence training have adequate safety features such as emergency egress panels, emergency lighting, ventilation, and a temperature monitoring system to measure the ambient temperature inside the maze.