New York City Health Department officials are investigating a cluster of 22 cases of Legionnaires' disease, including one death, in Central Harlem

Legionnaires' disease can be fatal, especially for older adults, smokers and those with weakened immune systems.

At least 22 people have fallen ill, including one person who has died, from Legionnaires’ disease in New York City over the last two weeks, according to the city’s health department. City health officials believe that the people most likely became ill after breathing in bacteria sprayed from a cooling tower in central Harlem.