Abstract: Employee #1 was operating a 10-ton rear mounted hydraulic truck crane. The crane was used to set 13,500 and 15,000 pound concrete vaults inside trenches. The crane was on a 40-foot heavy duty trailer bed and was attached to the rotating ring by 36 2.5-inch flat counter sunk socket head screws. At approximately 11:30 p.m. on May 31, 1989, Employee #1 cleared the trailer bed with a 13,500 vault when he heard a loud popping noise. Six of the screws sheared off and 31 pulled out of their sockets. The pedestal base pulled out, throwing Employee #1 to the ground. The crane fell across his chest, crushing him to death.