Abstract: On January 13, 1989, Employee #1, an assistant driller for B.A. Tec Assoc., Inc., Columbia, MD, and a coworker were boring a hole with a Mobile drill rig (Model No. B-61). They needed to obtain soil samples to determine if the water was contaminated. The employees had secured a 5-ft-long, 3.03-ft-diameter hollow auger about 3 ft into the ground. Suspended above the auger by the rig hoist was soil sampling spoon attached at the lower end and a 5-ft-long rod attached to the top. The rod guided a 140-lb hammer as the rig cathead hoist raised it. A ring was secured to the hammer which, when released, was designed to freefall 30 ft and drive the spoon into the ground. Employee #1 was operating the hammer with the cathead as he steadied the rod with his hands. After striking more than 100 blows, the ring separated from the hammer at the point where the rod entered the top of the hollow stem. The free hammer fell down the rod, striking Employee #1's hand. He was hospitalized for his injuries. Employees were instructed not to hold the drill rods with their hands. The company had a safety program and provided personal protective equipment.