NORTH HAVEN, Conn. (AP) – A 3-year-old boy visiting from Rhode Island has died in a pool at a family gathering for the July Fourth holiday.

Harrison Marsocci of North Scituate, R.I., had been watching television indoors but slipped outside unnoticed, police said. Family and friends found him in the backyard pool after 9:15 p.m.

Police said they were called to the house on a report of a drowning but medical examiners had not determined the cause of death early Tuesday afternoon.

Rescue workers were unable to revive the boy and took him to Yale-New Haven Hospital, where he was pronounced dead.