New York City will launch stricter rules for cooling towers after one of the worst Legionnaires’ outbreaks in years broke out in Harlem. The city Health Department plans on ramping up enforcement, penalties and reporting requirements for building water systems that are considered the source of many cases of Legionnaires’ disease.

Legionnaires' disease is caused by Legionella, a bacteria that can travel through water systems and devices. Although most healthy people don't contract it, it can be deadly for those who do.

New York City health officials are continuing to investigate a cluster of Legionnaires’ disease, a serious bacterial lung infection, where the number of cases has risen to 73, including three deaths.