On March 23, 1998, three male fire department members and a female automobile crash victim died of injuries sustained in an air ambulance/ helicopter crash. Additionally, two other fire department members were injured in the crash. The helicopter was dispatched at 0716 hours to a multiple vehicle crash site. After landing, a female crash victim was loaded into the helicopter. The helicopter lifted off the ground and proceeded in a south-southeasterly direction toward a pediatric trauma center at 0732 hours. The helicopter was airborne about 7 minutes when an apparent tail rotor failure caused the helicopter pilot to lose all but partial control of the helicopter. The pilot tried to maneuver the helicopter to an open area for landing, but the helicopter impacted trees, which turned the helicopter on its left side plunging it to the ground at about 0740 hours. The helicopter struck the ground on its left side and left nose section. A park ranger observed the forced landing and after extinguishing a small fire near the engine, called for assistance via his radio. Between 0747 and 0752 hours several rescue units arrived on scene, removed the victims from the helicopter, and transported the two injured victims to a nearby hospital. NIOSH investigators concluded that, in order to prevent similar incidents, fire departments utilizing helicopters for various reasons (e.g. air ambulance, water rescue, etc.) should review Operators Manuals, Training Bulletins, and pertinent information regarding air operations safety and procedures, and update standard operating procedures as appropriate. Additionally, manufacturers should take steps to ensure that manuals regarding helicopter operation and maintenance are clear.