A five-year-old boy shot and injured his four-year-old friend in a playground in Maryland.
Police are investigating how the little boy managed to get hold of the gun, believed to be a 0.22-calibre pistol, reports Daily Mail.
After firing at his friend, ran off with the weapon and hid in his family's apartment, while the neighbours carried the wounded boy into the building.
Both the boys were playing quietly when a loud bang rang through the neighbourhood.
The neighbour who came to the injured boy's recue said the boy was in shock, so she laid him on her bed and called police, then did her best to clean him up.
When police officers arrived they found the five-year-old shaking with fear inside his apartment, said the daily.
Neighbours said his 18-year-old sister had been looking after him while their mother was out at work.