Illinois State Police Trooper Calvin Dye Jr. reported that a driver of a semi for unknown reasons ran into seven cars on Interstate-55 at the 27.5-mile marker near Hamel at 6:14 p.m. Tuesday, leaving two known dead and 12 transported to an array of area hospitals, some in critical condition. The truck tractor is off the road and the southbound lanes of the highway near the crash site are closed late Tuesday night as officers investigate and clean up the scene, Trooper Dye said. It is unknown at this time when those lanes would be open. Dye said injured were transported to Mercy Hospital, Anderson Hospital, St. Louis University Hospital and Barnes-Jewish Hospital. Some of the injured were transported via helicopter. Dye said around 9:30 p.m. the truck tractor remained off the road. Edwardsville's Fire Department assisted in the tragedy and was incredibly busy late Tuesday night with the incident. Other EMS units were also called in for what became a massive casualty event. "It is one of the worst crashes we have had," Dye said. "When that many are transported to hospitals, usually it is a bus crash. Wednesday is also one of the busiest travel days of the year, so this came at a terrible time."