EE WAS HELPING CURTAIL TRACK. AS A RAIL WAS BEING LAID ONTO A FLATCAR, IT TURNED OVER, CAUSING EE TO TWIST LOWER BACK. HE DID NOT GO TO THE DR.UNTIL 5-13-02 (CONTINUED WORKING AT REG. DUTY), WHEN HE WAS TAKEN OFF WORK. HE RETURNED TO REG. DUTY ON 5-19-02.