Sky View Rehabilitation and Health Care Center in Croton-On-Hudson says some of their water has tested positive for Legionella.
The samples were taken prior to recent safety upgrades of their disinfection of their water system, according to officials.
Sources close to the family say 93-year-old Carmella Scafuri died after being diagnosed with Legionnaires' disease.
The other person diagnosed is still recovering in the hospital.