The fecker filled it in, pity... Bob, were they your neighbours ?
A good friend of mine drills wells for water and had a similar incident with his drilling rig. The machine was up on it's 3 hydraulic jacks and not long after he started drilling, one of the jacks literally fell into the ground and the whole rig toppled over. He tells me that he'd hit limestone caverns all the time. The machine could be drilling away at a steady pace then all of a sudden it would take off like a good thing, just falling down through what he presumes is a limestone cavern. Only problem is you'd have to be no more than 8" in diameter to fit down. I suppose you could always send a camera down with a big light on it
