FINISHED UNLOADING FINES TRUCK CA0 EE WAS HELPING THE DRIVER BY UNHOOKING BLOWER 3"" HOT LINE HOSE. NOT KNOWING THAT A VALVE WAS SHUT OFF, BACK PRESSURE HAD BUILT INT HE LINE AND IN RELEASING T HE CAMLOCK LATCHES, THE CAM COME BACK ATTACHED TO THE 3"" HOSE AND STRUCK EE ON THE UPPER RIGHT CHEEK.