AN UNINTENTIONAL ROOF FALL OCCURRED IN THE #1 RETURN ENTRY ON THE 1ST LEFT SECTION, 1 BREAK OUT BY SPAD 385, AND WAS 700 FT FROM THE ACTIVE FACE. THE FALL MEASURED 35 FT L BY 20 FT W BY 4 1/2 FT. VENTILATION WAS NOT AFFECTED. AREA HAS BEEN BREAKERED OFF AND WILL BE REHABILITATED.