The unidentified Fairfield County woman was found at 8:30 p.m., Saturday, June 6, by the woman's son when he went to the home on Jones Hill Road in Monroe.
According to Capt. Keith White, the woman's family became concerned when they could not reach her for most of the day.
That's when her son drove to the home and found her in the pool alone, White said.
First responders were called to the home, but White said a preliminary investigation led police to believe the woman died earlier Saturday.
Police are waiting for an official cause of death from the medical examiner's office, but believe she suffered some sore of a medical incident while swimming.
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