An unintentional roof fall occurred in the 004 unit intake at the 4+20 station entry #2, 1st N. Main off of the East sub Main. The fall did not affect ventilation, affect passage of men or cause personal injury. The fall measured 20 feet x 20 feet x 6 foot thick and will not be cleaned up. The area had been roof bolted with 6 foot fully grouted roof bolts.