On 11/21/06, an unintentional roof fall occurred on the 3rd South Sub Main travel way, #6 entry between #60 and #61 cross cut, which is the secondary escape way for #1 unit. This area was supported by 10' and 15' point anchor roof bolts, the roof fall measured: 20' in length, 18' in width and 12' to 15' in thickness. This roof fall will be cleaned up and the area re-supported.