Slurryable ore where the overburden is unstable and subject to collapse is mined from substantially parallel elongated main trenches connected by a perpendicular trench at the bottom of the mineral seam. A plurality of softwall mining devices supported by face equipment is placed in the perpendicular trench. The devices slurry the mineral material and move into the mineral seam as the overburden sloughs behind the mining devices. The subsided overburden is supplemented as necessary with injected material. Slurried mineral flows to the parallel trenches for removal to the surface. After the softwall devices have advanced the length of the parallel trenches, the devices are withdrawn and placed in additionally developed trenches elsewhere in the ore reserve.