"We are in a state of chaos. In the city in which I live, I hear and see examples of chaos almost every day. Little children are victims of senseless gun violence..."

Two years ago, 11-year-old Milwaukee schoolgirl Sandra Parks wrote these words in an award-winning essay about the murders tearing her city apart.

On Monday night, aged 13, she was shot by a stray bullet fired into her home.

Her frantic family called 911, but Sandra died at the scene.

The girl's mother, Bernice Parks, told police she had gone to bed early while her children watched TV. She woke to the sound of gunshots shortly before 20:00, and found her daughter bleeding on the floor.

"She said, 'Momma, I'm shot. Call the police,'" Ms Parks told TV station WITI. "I looked at her. She didn't cry. She wasn't hollering. She was just so peaceful... She didn't deserve to leave this world like that."