HOPKINS -- Health officials are investigating a cluster of five confirmed cases of Legionnaire's disease in the Minneapolis suburb of Hopkins.

The Minnesota Department of Health said Friday the people became ill between Aug. 4 and Sept. 1. Three are hospitalized, and two others were hospitalized and have recovered. The patients are all over the age of 50.

The state Health Department and Hennepin County health officials are still investigating the source of the outbreak.

The disease takes its name from an outbreak at the Pennsylvania American Legion convention in Philadelphia in July 1976. The bacterium believed responsible is found in soil and grows in water, such as air-conditioning ducts and storage tanks. The disease is not spread person-to-person.

More than 60 cases have been reported in Minnesota so far this year.