The number of cases of Legionnaires' disease continues to grow in Milwaukee.
Since June 1, 19 Milwaukee residents have been diagnosed with the illness. That's part of 27 total cases in Milwaukee County.
The Milwaukee Health Department says no single source of contamination or exposure has been identified. Milwaukee Health Commissioner Bevan Baker says all samples have come back negative.
The disease takes its name from an outbreak at a Philadelphia convention of the American Legion in 1976. Legionnaires' disease is a severe form of pneumonia caused by a bacterium known as legionella. The disease does not spread person to person. People get sick by inhaling the bacterium.
Health officials say possible sources can include large cooling towers, hot water tanks, decorative fountains and hot tubs.