EE was pushing a rock, on the side of the no. 4 belt tail piece, with a shovel, back onto belt when rock hit moving belt it spun around, bounced back to the side of the tail piece, struck EE's legs, causing EE to lose balance, fall onto belt conveyor. EE carried underneath belt crossover and down belt when EE grabbed a belt support chain and fell off belt. EE travelled about 40ft