At 1756 Engine 252 Medic 257 and Medic 259 responded to the 39 mile-marker Interstate 81 southbound for a reported Motor Vehicle Collision involving a tractor trailer overturned. Upon arrival units found the two occupants out of the vehicle. The tractor trailer had overturned and was laying beside the roadway. Approx. 20-30 thousand pounds of glass was on the trailer when it overturned. The battery cable was cut and units cleared the call at 1933.