A RUBBER TARP, USED FOR HOLDING THE FUEL LINE NOZZLE WHEN THE TRUCK IS IN MOTION, WAS REMOVED AND LYING ON THE TOP STEP AT THE REAR OF THE TRUCK. WHEN HE BEGAN DESCENDING THIS STEP THE METAL HOOK ON THE RUBBER STRAP CAUGHT IN HIS RIGHT PANT LEG CAUSING HIM TO LOSE HIS BALANCE AND FALL. HIS LEFT FOOT STRUCK THE GROUND FRACTURING TWO BONES IN HIS ANKLE. HE FELL 30 INCHES.