Abstract: At approximately 2:30 p.m. on February 17, 2012, several employees were assembling an American brand lattice boom crane with a capacity of 165 tons. The assembly had been completed and there were two sections of boom attached to the crane, the butt section which is used as the base for the main boom and a lifting section called a "hammerhead." The crew supervisor was operating the crane and Employee #1 was releasing the pins that attached to the rear of the Hammerhead to the front of the butt section. The pins are about 10 inches long and two inches in diameter. As Employee #1 removed them with a sledgehammer, he was standing under the booms where they were joined together. There were a set of wire ropes going from the top of the crane cab to a "bridle" over the end of the butt section, then on to the end of the Hammerhead. According to the operators manual, the bridle needs to be attached to the butt section prior to removing the four pins and no one was to stand under the two sections while there was tension on the wire ropes and the bridle was not attached to the butt section. Both Employee #1 and #2 omitted both steps and, as Employee #1 removed the pins, the Hammerhead section fell on him. The initial report did not provide a description of injuries that Employee #1 sustained as a result of the accident.