A roof Fall occurred in MMU 001-0 at survey station 1470 in #3 entry. Approx.18 feet of coal was mined at the face of #3 and the MBC pump went out. The unsupported roof was hanging for approx.1hr.20 min. Time and poor geologic conditions caused the unsupported roof to fall and rip out previously installed bolts. Outby the fall was bolted with 6 FT. bolts and 10 FT. Cables.