An 11-year-old boy escaped death in a shooting spree that killed six members of his family only because a gun pointed at his head misfired, police said.

The boy's mother, his aunt, three brothers, and a sister were killed one by one as the horrified boy watched, said Atlanta police spokesman John Quigley.

Gunman Cyrano Marks, 39, committed suicide.

The surviving child, Santonio Lucas, told police Marks summoned the entire family into the master bedroom of their home shortly before 6am on Monday after his mother told Marks she wanted to end their relationship.

Marks pulled a gun from his pocket and family members ran from the room, the boy said.

''He grabbed the 11-year-old by the arm and dragged him as he went from room to room, to each individual, and shot them,'' Quigley said.

The terrified boy watched as Marks killed his mother, then his aunt, then all of his siblings.

''The boy then pulled away and hid in the closet, but Mr Marks went to the closet, put a pillow on the boy's head, and pointed his gun at the pillow,'' Quigley said. ''He fired the gun, but for some reason it didn't go off.''

Santonio told police that Marks returned to the closet a couple of minutes later and fired one shot, which lodged in the boy's elbow. He pretended to be dead.

A few minutes later, the boy said, he heard the sound of one more shot being fired, presumably the one that killed Marks.

The victims were identified as Santonio's mother, Deleane Briskey, 33; her sister, Essie Jo Hugley, 37; and the boy's brothers and sisters, David Lucas, 13; Craig Briskey, 15; Antwan Lucas, nine; and Tosha Briskey, 16.

Eight hours after the shootings, the boy summoned the courage to leave the closet and go to a neighbour's home for help. He was still in hospital yesterday where doctors said his condition was stable.

''I'm devastated,'' said Gikeivia Johnson, a cousin of the family. ''It don't make no sense.''

Neighbour Betty Fuller said Santonio was a smart, happy-go-lucky child. ''He was just as sweet as he could be, and God had to be with him for him to hide,'' she said.-Reuters/AP