Abstract: Employee #1 was assisting the other drivers to offload oil field drilling equipment from trucks and trailers on a new drilling site using his truck. He connected his truck winch cable to a portable mud pit, a large tank that holds drilling fluid on the rig or at a mud-mixing plant, until one end of it was on the ground. He then backed up to allow slack in his cable, got out of his truck, and disconnected the cable. Employee #1 got back in the truck and moved it to a neutral location, got out, and walked over to the side of the portable mud pit that was still about halfway on the trailer of the other truck. The other driver drove forward until the portable mud pit fell to the ground. He continued forward 2 ft to 3 ft then began to backup to put slack in his cable from his truck to the portable mud pit. As the other driver was backing, Employee #1 walked between the trailer and the portable mud pit and was crushed, killing him.