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 the latest death Thursday as they revealed that some cooling towers tested positive for the bacteria in some city-run buildings.

The last of 12 cooling towers that tested positive for the bacteria currently spawning a Legionnaires’ outbreak in Harlem is being remediated Friday, with officials hoping containment efforts will help prevent another death.