Fifty-eight people in New York City have been diagnosed with Legionnaires’ disease, a serious bacterial lung infection, and two people have died, according to the city health department.

An outbreak of Legionnaires’ disease in New York City has killed two people and sickened 58 since late July. City health officials link the Central Harlem outbreak to cooling towers, structures containing water and a fan that are used to cool buildings.

The disease is a form of pneumonia caused by water contaminated with Legionella, which can be found in cooling towers, showers and hot tubs.