Emergency personnel responded shortly before 10:30 a.m. Friday to the report of a vehicle crash with a male subject struck in the roadway on I-255 southbound at milepost 11 north of Dupo.

Responding agencies assisting Illinois State Police and MedStar Ambulance on scene included the Dupo and Prairie du Pont fire departments.

Multiple lanes of I-255 southbound were shut down temporarily as a result of the incident.

ISP said preliminary information indicates that for unknown reasons, the pedestrian – identified by police as Sinan Memic, 54, of St. Louis – was in the roadway and was struck by a truck-tractor semi-trailer combination.

The pedestrian was transported to an area hospital with serious injuries, ISP said. There was no update provided on his condition as of Monday afternoon. The driver of the truck-tractor was not injured.