A Mississippi 3-year-old found in a locked vehicle Tuesday has died.

WJTV in Jackson reports that officials found the child unresponsive in the back seat of a family’s vehicle in Perry County. Officials say the windows were closed, and the doors were locked in the vehicle.

Officials say they are unsure how long the child was in the vehicle or how he got in.

An autopsy will be conducted to determine the child’s cause of death.

An investigation is underway. The Forrest County Coroner’s Office assisted in the case.