A 9-year-old girl was accidentally shot and killed by her 3-year-old brother Saturday afternoon in Irondale.
Chief Ken Atkinson said the girl was shot in the head and initially suffered life-threatening injuries.
The girl later died after being flown by medical helicopter to Children's of Alabama, police say.
The shooting occurred at around 2:10 p.m. in the bedroom of the children's grandparent's house on Monroe Drive.
"It appears to be a tragic accident," Atkinson said, but the shooting remains under investigation.
Atkinson said 3-year-old boy found a loaded pistol on a bedroom nightstand and shot his sister.
The grandfather had left the loaded gun on the nightstand not knowing his grandchildren were coming over that day, he said.
Atkinson said detectives are interviewing the children's uncle and grandmother who were home at the time of the shooting to learn exactly what happened.
"The lesson is you have to make sure those weapons are put up, out of sight and out of reach, really of anyone, but especially children," he said. "It is tragic because this 3-year-old has no idea what is going on right now. It is just a horrible situation."
Atkinson said he didn't know if the children were residents of Irondale.
Monroe Drive is a dead end roadway near Interstate 459.