On March 31, 2006, the FF/EMT arrived for duty at his fire station (Station 4) at 0745 hours. The three crew members assigned to Station 4 checked their fire apparatus and equipment, and then the FF/EMT washed the station's vehicles (one engine and one ambulance). No calls or alarms were received by Station 4's crew during the day. At approximately 1630 hours the FF/EMT was last seen walking around the apparatus bay. At 1656 the FF/EMT was found lying face down, unresponsive, without a pulse or respirations in the apparatus bay. Despite cardiopulmonary resuscitation (CPR) performed at the station, and advanced cardiac life support (ACLS) performed in the ambulance and in the emergency department (ED) of the local hospital, the FF/EMT died. The death certificate, completed by the examining physician in the hospital's ED, listed the immediate cause of death as "probable cardiac arrhythmia," due to "seizures," due to "epilepsy." The autopsy, completed by the county coroner's office, concluded the FF/EMT most likely died of a "sudden unexplained ventricular arrhythmia or possible seizure." The NIOSH investigator concurs with this conclusion. The NIOSH investigators offer these recommendations to reduce the risk of on-the-job sudden death among fire fighters: 1. Encourage fire fighters to provide accurate medical history information to the FD physician. This can be accomplished by emphasizing the importance of this information during training sessions. Physicians providing medical clearance for duty should be knowledgeable about the physical demands of fire fighting, the personal protective equipment used by fire fighters, and the various components of National Fire Protection Association (NFPA) 1582, Standard on Comprehensive Occupational Medicine Program for Fire Departments. Although unrelated to this fatality, the FD should consider the following recommendations to improve their overall safety and health program. 1. Conduct exercise stress tests (EST) for fire fighters at increased risk of ischemic heart disease. 2. Discontinue resting electrocardiograms (EKGs) performed as part of the annual medical evaluation program. 3. Phase in a wellness/fitness program for fire fighters to reduce risk factors for cardiovascular disease and improve cardiovascular capacity. 4. Phase in a physical performance (physical ability) evaluation to ensure fire fighters are physically capable of performing the essential job tasks of structural fire fighting. 5. Use a secondary (technological) test to confirm appropriate placement of the endotracheal (ET) tube during emergency intubations. 6. Conduct periodic testing of ACLS equipment and refresher ACLS training for fire fighter/paramedics.