The Health Department has confirmed that two Co-Op City residents have been diagnosed with Legionnaires' disease, a serious form of pneumonia that could be deadly.

People who live in the building say a notice from the Health Department was slipped under their door and posted in the lobby last week. Health officials say the two residents live at 120 Alcott Place and were diagnosed within the last 12 months.

The Health Department says it is evaluating the water system at the building and alerting residents of the situation.

"Of course I am concerned, this is not the first time, there has been at least one other time I know for sure," said Lloyd who lives in the building.

Multiple cases of Legionnaires' disease have been traced to different buildings in Co-Op City over the last decade, including in 2018 when one person died from complications.

The disease is contracted by breathing in water vapor containing the legionella bacteria.

It is not contagious, and it can be treated with antibiotics.

Health officials say people can still drink water, but people who are at higher risk of contracting the disease should take precautions.

People over 50 years old with underlying health conditions are at high-risk.

The Health Department advises those at high-risk to not take a shower, even with cool water, instead a bath is recommended.

They are also advised to fill the sink slowly to avoid creating mist and continue to wash their hands. Health officials say it is OK to drink cold water from the tap.

Riverbay Corporation has not responded to News 12's request for comment at the time of this report.