The Illinois State Police said it is investigating a fatal pedestrian traffic crash early Saturday morning on I-255 near Grizzlies Ballpark.

Police said the incident occurred shortly after 2:50 a.m. on I-255 northbound near milepost 15 in St. Clair County.

Initial reports indicated a Freightliner semi tractor-trailer struck and killed a female pedestrian, who was identified by a coroner’s official as Marlene M. Harper, 46, of Maryville.

Traffic was re-routed off I-255 northbound to the Mousette exit during the crash investigation, ISP said.

The roadway was re-opened at approximately 8:16 a.m.

“This is an active investigation and no additional information is available at this time,” ISP Trooper Genelle Jones said Saturday afternoon.