His research had mentioned that the dwarves had abandoned the mine almost immediately after the collapse; the official reason stated, as much as dwarves share their reasons, was that the vein was mostly tapped out, and it wasn't worth the investment to attempt to clear out the rubble.<br/><br/>The dragon was still napping, when he returned, though he can see, as she idly half-opens one eye to look as he approaches, that she's not entirely asleep.