Abstract: Employee #1, the foreman at a surface mine, was assisting in measuring the proposed location of a stacker conveyor by holding the end of a 200 ft long measuring tape underneath a discharge chute of a screened 1/2 in. rock bunker. At the same time, the driver of a 10-wheel haulage truck was reversing to a position beneath the same bunker to take on a load of rock. The truck driver did not see Employee #1, who blended with the dapple-shadowed background. Employee #1 had his back to the haul truck and did not hear the operating back-up alarm because of the high ambient noise in the immediate area. The truck knocked Employee #1 to the ground and ran over his lower legs. The driver was then alerted to the occurrence by a coworker conducting measurements, who ran to the scene and signaled him to stop.