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.

Legionnaires' disease has killed at least five in New York and sickened many more, but its risk factors are widespread and growing across the US.

A 2015 outbreak of Legionnaires' disease, traced to a cooling tower at a hotel, forced New York City to address a problem that had long been suspected but never adequately addressed: the role of buildings in spreading Legionella bacteria through the air.

A sixth person has died from Legionnaires’ disease connected to the outbreak in Central Harlem, health officials announced on Wednesday. The patient died outside of New York City earlier this month. The city’s health department reported that 111 people have been affected by the disease,

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

Victims of the deadly Legionnaires’ disease outbreak gripping Harlem will sue the Big Apple for allegedly letting bacteria fester in city-owned cooling towers, it was announced Wednesday.