The injured employee was standing on the ground observing and acting as a fire watch while two other employees were working to remove a channel from the top of a wood pellet bin. The employees removed both nuts and one bolt (leaving one bolt in place) on the left side, then went to the right side and repeated the process. This was in preparation for the crew to attach a chain and choker to hoist the channel off the bin. Prior to attaching the chain and choker, the pressure or weight of the channel caused the bolts to shear and the channel to fall to the ground striking the injured employee on the back of his hardhat. The injured employee fell to the ground, resulting in injury to their shoulder and ankle as well as a laceration on the back of the head.