Homicide detectives determined Tuesday that the death of a 3-year-old boy in Valencia who drowned the previous night was accidental, according to the Los Angeles County Sheriff’s Department.

The drowning occurred in the 27600 block of Woodfield Place (map) shortly before 7:15 p.m. Monday, a Sheriff’s Department news release stated.

Based on initial information, it was believed the toddler possibly drowned while being supervised by underage relatives, according to sheriff’s Lt. Derek Sabatini.

The boy had been left in the care of family members between the ages of 14 and 19 years old, Deputy Mike Barraza stated in a news release.

At some point, the boy wandered outside and in an apparent attempt to retrieve a ball from the swimming pool, he fell in, according to Barraza.

Family members later found the child unresponsive in the swimming pool and performed CPR on the boy until deputies arrived.

The boy was later pronounced dead at the hospital.

The incident was ruled accidental and no criminal negligence was involved, Barraza stated.

The boy was not identified.

KTLA’s Justin Burton contributed to this story.