Abstract: At approximately 2:30 p.m. on March 18, 1991, the employees of the firm were engaged in the demolition of a railroad trestle. At the time of the accident they were dismantling the trestle system with a Grove 18-ton crane with a 60-ft boom. The crane was located on the west side of the river and was setting on three 2-inch steel plates. Each plate was 6 ft by 10 ft. The outrigger jacks were down against the steel plates, but were not extended. The crane picked up an A-frame weighing approximately 5000 lbs. The distance from the pick point to the center pin was 40 ft. After the operator lifted the A-frame, he shortened the boom about 6 ft, and started to swing the A-frame to the south in order to land it on the river bank. Just as the swing-arc came across the front corner of the crane, the back left corner of the crane started to lift up. A chain attached to the back of the crane to prevent it from tipping tightened, but the hook of the chain broke and the crane fell 30 ft to the river bank below. The operator and his helper were able to escape the tipping crane and were not injured.