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.

The outbreak in New York City began in July, which affected dozens of people with severe Legionnaires' disease. The health department confirmed that 17 others are hospitalized as of Friday.