The crash happened at about 3:15 a.m. in the Stevenson Expressway's northbound lanes at Harlem Avenue near Chicago's Garfield Ridge neighborhood, ISP said. A 12-year-old was a passenger in a vehicle when, for unknown reasons, it lost control and rolled over.
The child, who was ejected from the vehicle, was transported to a local hospital, where she were pronounced dead, ISP said.
The girl has been identified as 12-year-old Jennifer Lopez, of Gage Park, according to the Cook County Medical Examiner's Office.
All northbound lanes were closed for the crash investigation and traffic was rerouted at Harlem Avenue, ISP said. Police did not immediately provide further information about the crash.