A UNINTENTIONAL ROOF FALL WAS AT STATION AND 1943 ABC MAIN WEST INTERSECTION ON BELT LINE. FALLW AS 20 FT LONG 18 FT WIDE 10 TO 12 FT HIGH. THE AREA HAD BEEN BOLTED WITH 6 FT SUPER BOLTS WITH ADDITIONAL SUPPORTS INSTALLED. THERE WERE NO INJURIES OR EQUIPMENT INVOLVED.