Did gold miners ever get lost in the mines?

Sure, if the lights ever went out, or there was a cave in or if they got lost in an unmarked passage, or if there was only one or two people working a big mine. Yes, working in any kind of mine can be dangerous, and quite of few people have gotten lost and died in mines, including gold mines.

Too bad (for the miner) if a great big hungry bear decides to use the mine as a substitute for a cave to hibernate in and the miner does not have any weapons to defend themselves.