Three people have died in a Legionnaires' disease outbreak at an assisted-living facility in upstate New York.

A cluster of cases was discovered last Friday at Peregrine Senior Living at Shaker in Albany, health officials said.

A total of 10 people tested positive. Two of the people who died had been hospitalized for other health issues before the disease was discovered, according to the Albany County Health Department.

Officials said 20 people from the facility had been hospitalized since last week, but some have since been released. The conditions of those still in the hospital is unknown.

Water samples from Peregrine tested positive for the bacteria that causes Legionnaires' disease and further testing is being conducted, the facility said. In the interim, additional safety precautions have been put in place, including providing the residents with bottled water.

"Since that time, we have installed advanced water filters in as many locations as possible, including in designated bathing and showering locations," Peregrine executive director Kristyn Ganim said in a statement.

Legionnaires' disease is a serious type of pneumonia caused by Legionella bacteria, according to the U.S. Centers for Disease Control and Prevention.

It's contracted by breathing in water mist that's infected with the bacteria, such as from a hot tub or shower. It's not contagious and cannot be spread from person-to-person.

The illness requires treatment with antibiotics, but about 10% of those infected develop fatal complications. That percentage shoots up to 25% for those infected while in healthcare facilities.