The suspect fired at the 7-year-old and 6-year-old at approximately 2:50 p.m. while they were in a car on the 6200 block of West Grand Avenue, Chicago Police said.
The 6-year-old girl sustained a gunshot wound to the chest and the right armpit. The 7-year-old was shot in the chest and the torso. Both were transported to Loyola University Medical Center, where the 7-year-old was pronounced dead. The 6-year-old is in stable condition.
Police did not disclose if the two girls are related or other the circumstances surrounding the shooting.
As of Sunday evening, 42 people had been shot in Chicago over the weekend, four of them fatally, police said.