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.

The deadly Legionnaires’ outbreak gripping Harlem has city officials in hot water — as locals accused them Friday of dropping the ball on life-saving inspections and needlessly slow-walking revealing exactly where the disease hit.

Symptoms mimic the flu but escalate quickly. Watch for cough, fever, chills, muscle aches, shortness of breath, and sometimes headache, confusion, diarrhea, or nausea. Symptoms usually show up 2–14 days after exposure.