Here is a diagram of what happened, zoomed out from the side. Note the reason for operating scoops by remote control in long hole stopes is to prevent loss of life in this type of operation. You can lose a machine, but not a life. Normally, long hole stopes are designed to remain open at least for as long as it takes to clean them out, but sometimes poorer local ground conditions or faults can result in a partial or total collapse of a long hole stope with a machine inside.
@NeilRingdahl Wouldn't know much about the support regime being used on this mine , but Wouldn't 6m to 10m long CAblE anchors prevent the stopes from caving in prematurely?