Abstract: At approximately 6:00 a.m. on August 29, 2007, Employee #1 and three coworkers moved a disassembled American Model 8460 165-ton lattice-boom truck crane, Serial Number GS19898, from Pit Number 2 to Pit Number 3. Coworker #3 parked his flatbed tractor trailer, which was loaded with counterweights and a section of boom, parallel to the crane, approximately 10 ft away. They began to set up the crane and coworker #1 raised the 50 ft boom and swung it towards the truck so that coworker #3 could release the travel slings from the main and auxiliary lines. At this point the main block and the headache ball were both approximately 1 ft from the truck, in between the truck and the crane. The main block was approximately 25 ft above the ground and had two 20 ft slings attached to lift the counterweights for the crane. Employee #1 was standing on top of the stacked counterweights on the trailer, approximately 8 or 9 ft above the ground. He was inserting hooks that would be used to lift the counterweights. The auxiliary line was hoisted with the 750 pound headache ball attached to a height of approximately 40 ft in order to get it out of the way. The left foot brake pedal for the auxiliary line failed to latch properly. The parking brake takes 2 to 3 seconds to bleed off air and completely set. The auxiliary line and headache ball began to free fall. The ball glanced off of the main block kicking it towards Employee#1. Employee #1 caught a glimpse of the ball coming down and put up his right arm over the side of his head. He was struck in the wrist and the head and knocked off of the counterweights and onto the ground. He suffered a broken wrist that required surgery, severe scrapes to the left side of his face, a bruised left knee, a sprained cervical spine, and a neck injury. Employee #1 was hospitalized.