I-55 was shut down in both directions between mile markers 52 and 60 (Route 16 and 108 exits) early this morning after a messy wreck involving a semi and a dump truck.   State Police report the driver of tractor trailer rear ended a dump truck at mile marker 56, between the Carlinville and Litchfield/Gillespie exits.  The impact caused both vehicles to veer left into the median where the dump truck rolled over on its side.  The tractor trailer caught fire in the cab area.  Both drivers were transported to the hospital with minor injuries.  The Litchfield Fire Department reported a semi-tractor fully involved and the dump truck spilled on the roadway.  Due to water supply issues, Raymond-Harvel FPD was requested mutual aid for an engine and a tender. Approximately 6000 gallons of water were used to bring the fire under control . The semi-trailer was heavily involved in fire as well and the contents werewacked tightly together in the trailer making it difficult for fire crews to reach the seat of the fire. The fire was brought under control after close to 3 hours and Raymond fire units were cleared from the scene. All of LFD units were cleared except for 802 which remained on scene to aid in the dismantling of the trailer and fully extinguishing the contents before it was removed from the interstate.  The Litchfield Fire Dept reminds drivers on the interstate to keep their focus on the roadway in front of them, especially at night, and to be cognizant of surrounding vehicles and the possibility of disabled vehicles in the roadway or on the shoulder. Highway speeds do not leave sufficient time to react to an accident or slow-moving vehicle. Be sure to leave plenty of room between you and the vehicle in front of you to ensure there is ample time make a defensive move in the event something should happen.