Nearly a dozen vehicles were damaged by rocks thrown from an overpass on the Stevenson Expressway near Pulaski Road on the Southwest Side.
In at least the third such incident in about a week, rocks rained down on motorists between 9:30 p.m. and 10 p.m. Wednesday near the Pulaski exit in the Archer Heights neighborhood, according to Illinois State police.
At least 11 motorists reported cracked windshields and other damage to their vehicles, authorities said.
State police suspect rocks may have been hurled by someone on a railroad overpass that runs parallel to the expressway.
No arrests were reported.
State troopers said the incident may have been a "copycat" of recent rock-throwing incident on Chicago expressways.
Authorities say rocks were thrown at motorists on the Stevenson between Pulaski Road and Kedzie Avenue on Saturday night.
Days before that, Chicago police said two boys, ages 14 and 15, threw rocks onto the Chicago Skyway and damaged several vehicles. That incident led to a brief shutdown of the Skyway.Copyright © 2015, CT Now