Abstract: At approximately 12:15 p.m. on July 23, 1990, Employee #1 was cleaning the concrete hopper at the rear of a concrete pump truck. He removed the grating over the hopper to chip out the hardening concrete near the grate corners. He sat over the left edge of the hopper and was chipping with a steel bar when he lost his balance and fell inside the hopper. At the same time, the pendant control fell from a ledge and struck the agitator control lever. The agitator began turning and caught Employee #1's feet as he was reaching to turn off the agitator control lever. He was hospitalized with a fractured ankle.