PHOENIX, Ariz. - Authorities in Arizona said an 11-year-old boy fatally shot his grandmother before turning the gun on himself after refusing to clean his room.

Az Central reports that 65-year-old Yvonne Woodard and her husband lived with their grandson in the Phoenix suburb of Litchfield Park, according to a Maricopa County Sheriff's Office spokesperson. The grandfather told detectives they asked the boy to clean his room, but he was "being stubborn about it."

The couple was sitting on the couch watching TV together when their grandson came up and shot his grandmother in the back of her head. The grandfather first ran after the boy before returning to his wife. The grandfather then heard more gunshots as his grandson shot himself, according to authorities.

The sheriff's office said the gun belonged to the grandfather. Investigators have yet to find anything that would indicate the boy wanted to hurt himself, or others before the shooting.