Lessons in emergency evacuation from the Miamisburg train derailment.

Hazardous materials incidents result from the release of materials considered to be harmful or potentially harmful to human beings or the environment. This article describes a train derailment and subsequent hazardous materials release with the evacuation of approximately 50,000 citizens. The hazardous materials release took five days to control and resulted in 561 patient visits to local emergency departments for symptoms related to chemical exposure. The evacuation and emergency medical operations are described and serve as a model for developing community emergency preparedness plans and managing victims involved in hazardous materials incidents.