THE EMPLOYEE WAS DESCENDING STAIRS INTO A BUCKET ELEVATOR HOLE TO PERFORM REPAIRS. HE SLIPPED ON THE STAIRS & TWISTED HIS RT.KNEE. HE RECEIVED FIRST AID (ICE PACK), BUT NO RELIEF FROM THE PAIN AFTER 2 DAYS. SOUGHT MEDICAL ATTN. ON 6/18/04 WAS GIVEN RESTRICTED WORK DUTIES.