The city health department is investigating two cases of Legionnaires' disease in Queens, which included a fatal one, officials said.

Officials said two people were diagnosed within a two-month period at 104-60 Queens Boulevard in Forest Hills.

One person has since recovered, according to the health department, while an elderly person with underlying health conditions died.

The health department did not specify when the cases occurred.

The department is working with building management to test the hot water plumbing system for the legionella bacteria, officials said.

In the meantime, health officials said residents can still use and drink the water.

Symptoms of the disease are similar to the flu and include cough, fever, nausea, and stomach discomfort.

The bacteria are not usually contagious — although they can possibly spread in rare cases — and can be treated with antibiotics.

The health department said there are between 200 and 400 cases of Legionnaires' disease in the city every year.

Earlier this year, one person died and several others were sickened when a Legionnaires' cluster broke out on the Upper East Side.

In 2015, there were multiple clusters of Legionnaires' disease in the Bronx. More than 100 people got sick and 12 died in the largest one, which was clustered in the South Bronx.