FALL APPEARS TO HAVE BEEN THE RESULT OF HIGH LATERAL GROUND STRESS ACTING UPON A LOW ANGLE FAULT ZONE. THIS AREA HAD BEEN INACTIVE SINCE JUNE 2000 DUE TO ADVERSE GROUND CONDITIONS. THE AREA IS 165 FT LONG BY 45 FT WIDE AND APPROX 20 FT ABOVEROOFLINE. THERE WAS NO EQUIPMENT DAMAGE OR PERSONAL INJURIES.