A 5-year-old girl was fatally shot and her 4-year-old brother wounded in an accidental shooting on Saturday by their 8-year-old brother, police said.
The children were home alone in a Jacksonville apartment when the shooting occurred, Jacksonville Sheriff's Office Chief Chris Butler said.
Butler said the elder boy fired a single shot from the gun, which killed his younger sister and gave his brother a non-life-threatening wound. Emergency personnel tried to save the girl, but were unsuccessful.
"We believe, in the absence of any other information being developed, that unfortunately this is a tragic unfortunate accidental shooting," Butler told The Florida Times-Union.
The children's mother had left for an unspecified amount of time to go to a store, Butler said. He did not release the names of the family involved.
A therapist was brought in to help the boy who fired the shot, Butler said. The Florida Department of Children and Families and the state attorney's office were also being consulted.
It was unclear to investigators how the child got access to the gun, or whether it had been properly stored and secured.
Butler said the incident is under investigation to see if any charges will be filed for leaving a gun accessible to the children.