Ambulance crashes are one of many hazards faced by Emergency Medical Services (EMS) personnel. Although no complete national count of ground ambulance crashes exists, the total number of fatal crashes involving ambulances can be ascertained by using the National Highway Traffic Safety Administration (NHTSA) Fatality Analysis Reporting System (FARS). To characterize risk factors for EMS workers involved in ambulance crashes, CDC's National Institute for Occupational Safety and Health (NIOSH) and NHTSA investigated three case reports of ambulance crashes. This report summarizes these investigations, presents surveillance data, and discusses recommendations for prevention measures. NIOSH is identifying and testing alternative measures to reduce injury risk for EMS workers.