On June 9, a state epidemiologist found, via laboratory surveillance, three cases of Salmonella Agona. The cases had attended a graduation party in Marshall, Minnesota, that had been held at a private home. The hosting family was contacted as part of the investigation. A guest list was created, and guests were contacted to find more cases. A total of 24 cases were identified. Salmonella Agona was isolated from one additional person's stool sample. Analysis of the food histories of cases and controls found that the hot turkey sandwiches were significantly associated with illness. Leftovers of the turkey tested positive for Salmonella Agona of the same genetic subtype as the stool samples (SA67). The hostess received the turkey from a relative who owned a turkey farm. The bird was cooked in early May, carved, and then frozen. The day before the graduation party, some of the turkey was thawed for both sandwiches and turkey soup. The samples submitted for testing came from the soup and from a portion of the sandwich turkey that had not been removed from the refrigerator.