WHILE TIMBERING AN AREA INBY THE FALL WHERE THE ROOF SHOWED SIGNS OF BEING BROKEN UP, THE AREA THAT FELL STARTED TO WORK. THE MEN TIMBERING WENT TO GET THE FOREMAN. WHEN THEY GOT BACK THE AREA HAD CAVED. THE AREA WAS BOLTED WITH 6' BOLTS & CABLE BOLTS INBY AND OUTBY THE FALL. THE AREA THAT FELL WAS BOLTED WITH 4' DOUBLE LOCK BOLTS.