A 12-year-old girl was taken into custody after she was accused of fatally stabbing her 9-year-old brother, police say.

“All homicides are tragic, but the second homicide of 2023 in Tulsa shows a definitive societal problem,” Tulsa Police Chief Wendell Franklin said in a statement on Twitter. “The question is, how does society address a child killing another child?”

The stabbing was reported shortly before midnight Friday, according to the police department. When officers arrived at the home, paramedics and firefighters already were tryin to save the young victim, police say. The boy was taken to a hospital and surgery was performed, but he died of his wounds.

According to police, the children’s parents were asleep upstairs when the girl woke one up and said she had stabbed her brother. Police did not say if they are aware of a possible motive for the stabbing.

The girl was taken to the Family Center for Juvenile Justice, police say. The police department’s Child Crisis Unit is investigating the stabbing.

According to ABC News, in Oklahoma any child under the age of 13 cannot be prosecuted as an adult for felony allegations of murder.