Abstract: On June 12, 1995, Employee #1 and his coworkers were setting up a lattice boom American 93W crawler crane to dismantle a nonactive oil refinery. Several weeks before, the crane had been used in the conventional boom mode until heavier pieces of equipment required that the boom be changed to a "skyhorse" configuration. On the day of the accident, the crane was resting on wooden crane mats when the operator tried to lift a 245,000 lb, 80-ft-high cylinder reactor. The total weight including the rigging was 256,000 lb and the operator applied 270,000 lb of force to the crane. The decision was then made to cut off the anchor bolts to free the reactor. Immediately after the bolts were severed, the reactor drifted to the left off the foundation. The front left side of the crane and mats sank into the ground. The reactor was resting on its end just in front of the crane when 32,000 lb of additional counterweight was put on the crane. Shortly after this weight was added, the main boom failed, fell, and struck Employee #1, who was standing approximately 20 ft from the reactor. He was killed.