A 3-year-old child shot and killed a 1-year-old sibling with a handgun that had been left unsecured in a home in San Diego in California, sheriff's authorities said.
It was not immediately clear who reported the shooting on Monday morning or where the children's parents were at the time of the incident.
Deputies in Fallbrook arrived and found the 1-year-old girl, who had a "head injury," the department said.
The child was taken to where she died an hour later. The did not release the name of the child who was fatally injured.
The department's Homicide Unit is working to gather more information about the incident, investigators said.
