Sixty-two-year-old Bharat Patel, his 33-year old daughter-in-law Nisha Patel and her 8-year-old daughter were found unresponsive in the above-ground pool Monday afternoon by East Brunswick police responding to a 911 call from neighbors who heard screams.
East Brunswick Lt. Frank Sutter said the young girl had fallen into the pool, and her grandfather and mother were trying to save her when they, too, began to drown, NJ.com reported.
Authorities said that while the above-ground pool was mostly shallow at 3 1/2 feet deep, a portion of the pool was 7 feet deep and "It doesn't appear that the victims knew how to swim."
The county's regional medical examiner determined the cause of death to be drowning and ruled the manner of death as accidental for all three victims.
The investigation is continuing, and anyone with information is asked to call police or prosecutors.
-- The Associated Press contributed to this report.