Rainwater left untreated in cooling towers atop city-owned Harlem Hospital fueled the Big Apple’s deadliest Legionnaire’s disease outbreak in a decade, the Rev. Al Sharpton charged Tuesday.

A law firm filed a lawsuit Aug. 20 against a New York City hospital’s construction company, alleging the company failed to treat bacteria-infected water in its cooling towers, leading to a Legionnaires’ disease outbreak.

A Legionnaires’ disease outbreak in Harlem has claimed a fourth life, with nearly 100 confirmed cases and more than a dozen people still hospitalized. For the first time, city officials have identified 12 cooling towers that tested positive for Legionella bacteria — including four city-owned buildings such as Harlem Hospital.

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

Lawsuit filed after a deadly Legionnaires' outbreak in Harlem, alleging negligence by construction firms and NYC.

All 12 cooling towers in Central Harlem that tested culture positive for live Legionella bacteria have been fully drained, cleaned, and disinfected.

Legionella, the bacterium that causes Legionnaires' disease, was discovered in 12 cooling towers on 10 Harlem buildings, including a city-run hospital and sex heal