MARENGO — McHenry County Sheriff's deputies shut down part of Route 20 in Marengo Tuesday morning after cars ran off the icy roadway. The sheriff's office sent an alert asking motorists to avoid Route 20 around 8 a.m. Tuesday in Marengo. Deputies shut the route down from West Union Road to Interstate 90 because it was covered in ice, and multiple cars were stuck, Sheriff's Deputy Sandra Rogers said. No one was injured in the incident.