Abstract: Employee #1, the crew chief, was assigned to demolish and clean up the sites of buildings and structures damaged in the recent Los Angeles riots. A hydraulic boom truck, 12 ton capacity, had been modified by the installation of a solid steel extension on the boom tip. The crane was positioned and the hydraulic boom was extended in order to push over walls and parts of structures. The crane was to be moved to another push location when foreign material that had become wedged into the crane's load block caused a loop in the load cable, under the load block sheave. While he was attempting to free the load block, Employee #1's fingers were pulled into the sheave or struck by the sheave and injured.