Abstract: Employees #1 and #2 were repairing a 100 ft long portable radial stacker-type conveyor. Employee #1 was standing behind Employee #2 at the tail pulley, and was leaning against the support that extended between the axle and the main frame; Employee #2 was kneeling at the axle, under the main frame. When they removed the locking pins, the axle rotated, causing the main frame to suddenly descend. When this happened, the head pulley end of the main frame, which was not resting on its blocks, also descended and struck the blocks beneath it. The two lower bolts, which held together the second and third sections of the main frame, broke, and the main frame descended further. It struck Employee #1 on the forehead and he fell to the ground, sustaining contusions and a head laceration. Employee #2 was crushed between the conveyor main frame lattice crossmembers and the lower transverse strut bar and axle. He suffered a ruptured spleen and a serious laceration to his right forearm.