VICTIM'S 3/4 TON PICK-UP TRUCK WAS PULLING SHOVEL TRAILING CABLE AND HAD BECOME STUCK OR THERE WAS LOSS OF TRACTION; THERE WAS A 2ND PICK-UP HOOKED UP TO THE 1ST TRUCK WITH A 1""NYLON ROPE. TH E ROPE WAS PLACED ON A HOOK WHILE TOWING; THE HOOK ON THE TOWING TRUCK FAILED CAUSING THE HOOK TO SLINGSHOT THROUGH THE WINDSHIELD OF THE TOWED TRUCK, STRIKING THE VICTIM.