Abstract: At approximately 8:13 a.m. on April 22, 2005, Employee #1, a carpenter and cement finisher, was getting ready to dig a hole with a Kubota B21 tractor at a residential house construction site in Healdsburg, California. The proposed hole was located at the backyard, which sloped steeply away from the house. Before the accident, the tractor was parked about 2 ft from the house and about 6 ft from the proposed hole, with the backhoe facing towards the house and the loader towards the back fence. The backhoe was off the center of the proposed hole and needed to be moved by about 2 ft. While Employee #1 was trying to maneuver the unit into position, its gears disengaged from low to neutral and moved swiftly down the slope. He stepped on the brakes to stop the machine but it went sideways and toppled over. Employee #1 was thrown out of the seat to the ground and the unit fell on top of him. Both his legs were pinned to the ground by the tractor's rollover protective structure. He sustained torn thigh muscles and knee ligaments on the right leg and bruises on both arms and legs and the right side of the body. He was hospitalized for approximately 8 hours.