DETROIT – A sleeping 7-year-old girl was shot and killed when an officer’s gun went off while Detroit police were searching a duplex for a suspect in the slaying of a teenager, a police official said.

Assistant Chief Ralph Godbee said at a news conference Sunday that Aiyana Jones was hit in the neck by a single bullet and died at a hospital. Police said the girl was sleeping on a couch when she was shot. “This is any parent’s worst nightmare. It also is any police officer’s worst nightmare,” Godbee said.

Godbee said the officers set off a flash grenade as they entered the apartment with their guns drawn about 12:40 a.m. Sunday with a warrant to look for a suspect in the Friday slaying of a 17-year-old boy.

The lead officer encountered a 46-year-old woman immediately inside the house’s front room, and “some level of physical contact” ensued during which the officer’s gun went off, Godbee said. The officers had identified themselves as police, he said.

Charles Jones, Aiyana’s father, told the Detroit News the woman Godbee referred to was his mother and the child’s grandmother.

“They came into my house with a flash grenade and a bullet,” Jones said. “They say my mother resisted them, that she tried to take an officer’s gun. My mother had never been in handcuffs in her life. They killed my baby, and I want someone to tell the truth.”

Godbee said police do not believe the gun was fired intentionally.