Epidemiologists' attempts to locate victims (case finding) in the wake of a tornado can be greatly facilitated by their working with county health officials, local hospitals, law enforcement agencies, the American Red Cross and disaster management officials. Several sources of data on tornado-related injuries may be available. Local emergency medical service (EMS) officials may have information on ambulance transport and field medical activities. Patient records from physician offices, hospital emergency departments, and medical records departments may be an excellent source of injury data. County medical examiners, coroners, law enforcement officials, and the media may also provide additional information on tornado-related deaths. Local census information can be extremely useful in developing an estimate of the size of the affected population.