ERECTING NEW DUCT IN PLACE BY CRANE. THE DUCT WAS HUNG UP BETWEEN STEEL & WHEN IT CAME FREE, THE EE'S LEG GOT CAUGHT BETWEEN STEEL & CRANE CABLE. TAKEN TO DOCTOR. RETURNED TO JOB & WAS PLACED ON OFFICE DUTY FOR OBSERVATION. OBSERV. PERIOD WAS NOT COMPLETED: EE WAS INCARCERATED FOR UNRELATED ACTIVITY. POST-INJURY DRUG TEST: RESULTS POSITIVE.