An unintentional roof fall occurred on the 5A intake entry #3 at x-cut 57 (32+20 station). The fall measured 20'x 20'x 6' high. It did not affect ventilation or cause personal injury. It did fall on the primary lifeline but their are 3 intake entries and the panel is worked out. The intersection had been bolted with 6 foot fully grouted roof bolts.