The incident occurred in Orange County around 12:15 p.m. on Thursday, Sept. 12, on Aster Way in Wallkill.
According to Wallkill Police Lt. Robert McLymore, officers discovered the victim, a 79-year-old Sullivan County man from Rock Hill, unconscious and unresponsive while in the pool.
Officers and EMS immediately began life-saving measures, including CPR, McLymore said.
The victim was transported to Garnet Health Medical Center in Middletown by the Town of Wallkill Emergency Medical Services, where he was pronounced dead.
The name of the victim has not been released by police pending notification of the family.
This is a developing story. Check back to Daily Voice for updates.
Click here to follow Daily Voice Pearl River and receive free news updates.