Authorities say it happened early Sunday morning in the 500-block of West Englewood Avenue.
Police say a man grabbed her from behind and dragged her into a vacant lot near the viaduct. The offender then allegedly beat and sexually assaulted the girl. She managed to run home and call police.
The attacker is described as a black man, 25-30 years old, 5'5" tall, muscular build, dark complexion and low box haircut. The offender was wearing a brown and white checkered shirt and dark blue pants.