Abstract: At approximately 3:10 p.m. on January 23, 1986, a 1969 Bucyrus Erie Model 45C 30-ton Mobil and 1 cubic yard concrete bucket were being used to pour two outer columns of the second level of a 2-level parking deck. Employees #1, #2, #3, and #4 were working in the same vicinity of the first deck above ground plumbing up inner columns. The deck above them was being formed up for a future pour. The crane was sitting around the corner from the two columns being poured and had to swing up over the corner so that the concrete bucket was out of sight of the operator when the concrete was to be poured. The crane operator had to rely on foreman's signals. At one point, the crane became overbalanced and the boom came in contact with the second level deck, which collapse, resulting in the injuries of Employees #1, #2, #3, and #4. Employee #1 had broken ribs and internal injuries. Employee #2 had back and leg injuries. Employee #3 had bruised left leg, and Employee #4 had sprained back. Employees #1 and #2 were admitted to the hospital, while Employees #3 and #4 were treated and released.