Health officials are looking into two cases of Legionnaires' disease in Queens.
The patients lived in the same building on Queens Boulevard in Rego Park, and were diagnosed six months apart.
One of them is still in the hospital, but the other's been discharged.
Their building's water supply is now being tested for legionnella bacteria.
In the meantime, residents have been told they can continue to drink, cook, and shower with the water.
Between 200 and 400 cases of Legionnaires' are reported in the city every year.
There was an outbreak two months ago in Lenox Hill that sickened eight people.
A single source for that cluster was never determined.
And back in 2015, 12 people died and 128 got sick from bacteria released from a cooling tower in the South Bronx.