EE WAS OPERATING A MANTRIP WHEN A RIB ROLLED OFF IN FRONT OF THE MANTRIP. EE APPLIED HIS BRAKES AND WENT INTO A SLIDE ON THE TRACK. WHEN HE SLID INTO THE RIB ROLL A PIECE OF ROCK CAUGHT HIS SH IRT SLEVE AND PULLED HIS ARM BACKWARD. EE SUSTAINED A FRACTURE TO THE LEFT HUMOROUS.