Authorities say two people died after their truck ran off a southern Illinois road and overturned in a water-filled ditch.  The Belleville News-Democrat reports 20-year old Christopher Harper of Saint Rose, Illinois and 18-year old Josie Lee Walker of Damiansville, Illinois died Sunday in Clinton County.  Clinton County Coroner Phil Moss says Harper lost control of the truck, which landed in the ditch near New Memphis that was filled with about 3 ½ feet of water from melting snow.  They were in the chilly water for about an hour and both died hours later at Saint Joseph’s Hospital in Breese.  Investigators say the road was covered with water from the snow melt.