On November 4, 2005, a 38-year-old male volunteer fire Captain was home when the fire department (FD) was dispatched to a medical call. As he began to respond, he collapsed. His wife found him getting up and complaining of breathing difficulty. He asked her to take him to the hospital instead of calling 911. Before he could get dressed, he collapsed again and his wife called 911. FD units and a mutual aid ambulance were dispatched and provided basic life support (BLS). En route to the hospital's emergency department (ED), the Captain became unresponsive, stopped breathing, and was pulseless. Ambulance service emergency medical technicians (EMTs), and FD crew members began cardiopulmonary resuscitation (CPR). Despite CPR and BLS performed by FD crew members and ambulance service EMTs, and advanced life support (ALS) performed by hospital ED personnel, the Captain died. The death certificate (completed by the County Coroner) and the autopsy (completed by the forensic pathologist) listed "pulmonary emboli (PE) due to probable deep vein thrombosis (DVT)" as the cause of death. The NIOSH investigator concluded that PE caused the Captain's sudden death. To reduce the risk of sudden cardiac arrest among fire fighters, NIOSH investigators offer the following recommendations: 1. Provide pre-placement and annual medical evaluations in accordance with National Fire Protection Association (NFPA) 1582 to determine fire fighters' 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 (CVD) 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 firefighting.