Abstract: Employee #1, a derrickman, and Employee #2, the driller, worked with a floorhand as part of a three-man oil rig crew. On their second day at the well site, they were working on the monkeyboard of a Wilson Mogul 42 workover rig, with a 96 ft crown-to-ground height, and a 55 ft board-to-ground height. They were positioned at the wellhead of an 11,000 ft pumping oil well to correct a pressure problem in the well apparently caused by a hole in the tubing. On the previous day the rig was set, the sucker rods removed and chained, and approximately 136 stands of 60 ft long pipe were racked. On the day of the accident, the employees had removed approximately 16 stands when there was a loud metal-to-metal sound as the rig shifted and overturned, and the mast collapsed. The floorhand and Employee #2 jumped from the platform, and the driller sustained multiple fractures. Employee #1 was tied off to the guardrail of the racking board platform, and the guardrail broke as the structure collapsed. He landed on the ground and was showered by falling pipe and sucker rods. Employee #1 was killed. There was no one trained to render first aid, the telephone and radio service were out of range, and no other transportation was available to summon medical assistance. The jackscrew pedestals were not securely fastened to the foundation beam supporting the mast, and only two guy lines had been erected. One was a chain around a small pine tree, and the other was a chain around an approximately 36 in. long by 2 in. diameter steel rod driven at an angle into previously disturbed soil. The steel rod pulled from the ground as the rig overturned. The employer did not follow the rig manufacturer's recommended specifications and the American Petroleum Institute Recommended Procedure #54 for the placement of the mast foundation, guy lines, and anchors, to ensure pull-out integrity for the anchors. There was no emergency escape line, no geronimo line, and no emergency action plan.