A new roof fall occurred on the South Mains ""B"" beltline between 28 and 29 x-cut. The fall was approx. 8 to 9' high by 18' wide and 60' long. Area was bolted with 8' Install III bolts and resin, H-beamed with 4"" beams sitting on cribs. Area was cleaned up and re-supported. Fall did not obstruct ventilation or escapeways. Cause of this fall was weather deterioration.