Abstract: At approximately 10:37 a.m. on January 30, 1991, Employee #1 was operating a 1972 Peterbilt #20 concrete mixer truck, model 348, serial #485680P, license #3P78554. He pushed the throttle control, which was located at the rear of truck, to spin the drum and was pumping the last remnants of concrete into the hopper of a 1983 Mayco concrete pump, model 12/30, serial #830411, when the truck suddenly jumped suddenly into reverse. The fixed ladder and the rear of truck crushed Employee #1 against the hopper frame. He was transported by ambulance to San Antonio Community Hospital, where he was pronounced dead. It is likely that the automatic transmission control was in reverse mode and the auxiliary gear was not in neutral position, causing the truck to move backward when the throttle control was accelerated. Employee #1 was an experienced operator/driver.