A deadly Legionnaires' disease outbreak in New York City has set health and community leaders on a campaign to educate the public on ways to prevent the bacteria from growing and spreading. Health leaders hit the streets of Harlem for a third straight day Friday with fliers urging people to take precautions as the number of infections continues to rise.

Here’s what to know about Legionnaires’ disease, how it spreads, and the East Harlem cooling tower outbreak under investigation.

A Legionnaires' disease cluster in the Harlem area of New York City has caused three deaths and over 80 people to be sickened. Here's what it is, symptoms and how it's spread.