AT APPROX. 4:45 AM A FALL WAS FOUND IN THE NSM RETURN AT ENTRY # 3 AT X-CUT 61. A STOPPING WAS DAMAGED AS A RESULT OF THE FALL. A J ORDER WAS ISSUED AND LATER MODIFIED TO A K ORDER TO ALLOW US TO PROP ALL 4 SIDES TO THE FALL, BUILD A CRIB ON THE TRAVELWAY AND THEN RESTORE VENTILATION. THE FALL MEASURED APPROX. 25FT. IN LENGTH, 20FT. WIDE AND 9FT. HIGH.