The Legionnaires' disease outbreak in Harlem has been traced to 12 cooling towers, including several at city-run buildings, officials said.

A fourth person has died in connection with a Legionnaires’ disease outbreak in New York City, health officials disclosed Thursday as they revealed that some cooling towers that tested positive for the bacteria are in city-run buildings.

Four people in New York City's Harlem neighbourhood have died from an outbreak of Legionnaires' disease, an aggressive and potentially deadly form of pneumonia. The city has seen 99 confirmed cases with 17 people in hospital with the infection, according to the New York City Department of Health.