Cave ins can happen when the walls and ceilings of underground mineshafts have not been properly secured. Also if a mine shaft is too deep cracks can happen in the floor and walls of the shaft making it weak.
Mining equipment is really large,heavy and can move at fast speeds. Mining equipment can put miners in great danger of being crushed,pinned or run over by mine trucks. To ensure that accidents stop happening. The CAD have helped protecting miners truck crashes.