When a tragic story of a family member vanishing happened a century before your time, so that you can do nothing to change it + the family are all dead, it used to be that was it. Probably still is. But now that I have seen topics here on tracing named members of families, I gotta just try the question.
A ship's boy in the 1870s, of which there were many then, often with bad aspects to their working conditions. This one had a very ordinary name, Tom Lewis, b1860 Cardiff, at age 14 joined ship HMS Ganges af Falmouth, which ship recruited boys there throughout the late C19. I traced its staff list of 1881 + he is no longer in it.
Family story was, he went to a gold rush + was never heard of again.
I suppose it's most likely that the gold rush's ruthlessness was fatal + he never ended up in an unknown life somewhere, good or bad. It was thought to be Australia, but someone in a tree site who also had a seafarer in her family flagged up that there was a gold rush in South Africa in that period. Her folks did fine in it, settled in Oogies, Transvaal, + even married a Lewis but wrong gender to be him..
Are there any ways known in your skills, to fish for clues to what happened in such a case, so long after it?