A serious outbreak of Legionnaires' disease has struck Harlem, leaving two people dead and at least 58 others diagnosed with the potentially deadly form of pneumonia, according to city health officials.

The cluster of cases emerged last week, prompting an urgent investigation by the New York City Department of Health. The outbreak has raised concerns over contaminated plumbing systems commonly linked to Legionella bacteria — the organism responsible for the disease.

What is Legionnaires' Disease?

Legionnaires' disease is a severe lung infection caused by inhaling water droplets contaminated with Legionella bacteria. It is not spread person-to-person, and the illness most commonly arises from exposure to contaminated cooling towers, hot tubs, hot water tanks, humidifiers, and other water systems where the bacteria can thrive in warm conditions.

Symptoms to Watch For:

• Cough
• Fever
• Chills
• Muscle aches
• Shortness of breath or difficulty breathing

People with underlying health conditions, seniors, and smokers are considered at higher risk of developing complications.

Ongoing Investigation:

Dr. Jon LaPook, CBS News’ chief medical correspondent, reported that health officials are currently testing multiple building water systems in the affected areas of Harlem. Early reports suggest cooling towers are the most likely source, though investigations are ongoing.

City Response:

The NYC Health Department has increased monitoring and advised local residents to seek medical care immediately if symptoms appear. Public health teams are also inspecting and disinfecting suspected water systems in a bid to stop further transmission.