IN THE ELEVATOR REPAIRMAN'S OPINION THE INNER DOOR OPENING CABLE (WIRE) CAME LOOSE CAUSING THE ELEVATOR TO STOP SUDDENLY WHICH CAUSED THE SOS SWITCH TO KICK OUT. NO EMPLOYEES WERE ON THE ELEVA TOR AT THE TIME. THE ELEVATOR WAS BROUGHT TO THE COLLAR, SOS SWITCH RESET AND CABLE REPLACED. DONE BETWEEN 2:45 & 3:00 P.M.