Abstract: At approximately 9:00 a.m. on September 15, 1999, Employee #1, of Dudutis Tower Service, was using an American Aero pedestal-mounted marine crane with a 70 ft boom at a radius of 57.73 ft to lift the second of three sections of a main broadcasting antenna weighing approximately 13,000 lb. The crane was rigged with a two-part line, and two double blocks. The upper block was positioned approximately 2 ft below the tip of the crane's boom and approximately 10 ft below the top of the antenna. The lower block was positioned just above the metal flanges that separated the center and lower sections of the antenna. The tip of the crane's boom was approximately 2 ft away from the side of the antenna closest to the crane. The antenna was at a corner of a candelabra platform atop a 900 ft tall candelabra-guyed communications tower. The crane performing the lift was on top of a 50 ft tall false tower, centered over the candelabra platform. While lifting the upper two sections of the antenna, the antenna sections had separated approximately 6 in. to 10 in. from their base section when 20 of the crane's 24 mounting bolts broke. This caused the crane to lean forward over its mounting plate and push the antenna back down onto its installation location, simultaneously putting the antenna out of plum. This necessitated the evacuation of all television and radio studios, a nursing home, and residents within a 12-block radius of the tower. No employees were injured as a result of the incident. Subsequent investigation found that the crane was overloaded and that it had not been inspected by a competent person before use. The crane's twenty-four 3/4 in. by 3 1/4 in. mounting bolts were inadequate in size and number and they lacked beveled washers. The crane's mounting plate was not thick enough, nor was the top 20 ft of false tower on which the crane was installed.