CHICAGO (AP) — Chicago police say a 7-year-old girl was fatally shot and her 6-year-old sister was seriously injured when someone opened fire as the siblings sat in a parked car.

The 7-year-old was pronounced dead at a hospital after being shot Sunday afternoon in Chicago’s northwest side Belmont Central neighborhood. She was identified as Serenity Broughton by the Cook County medical examiner’s office.

Chicago’s police Chief of Patrol Brian McDermott said Sunday evening that her 6-year-old sister was “fighting for her life” at a hospital. He says the shooting happened as the girls’ mother was putting the two youngsters in the back seat of a car.