Tri-axle dump trucks were importing stone to the worksite. After one of the trucks emptied its load the injured employee noticed stone on the tail of the body where the tailgate would close. The employee notified the driver who, again, raised and lowered the bed of the tri-axle to dislodge the debris. When the bed lowered the employee's left hand was caught in a pinch point between the truck body and the tailgate resulting in amputation of the middle and ring fingertips.