A Legionnaires' disease cluster in the Harlem area of New York City has caused three deaths and over 70 people to be sickened. Here's what it is, symptoms and how it's spread.

Three people have died and at least 67 people have been diagnosed with Legionnaires’ disease in a cluster that broke out in New York City last week.

A Legionnaires' disease outbreak in New York City has infected 67 people and caused three deaths, the city Department of Health and Mental Hygiene said.