Here's what I'm choosing to think for the next little while ... many years ago, a much-loved child dies in the bush somewhere remote, maybe on a wheat farm miles from a hospital. The parents cannot bear to part with the body and keep it somewhere at home as a memorial, where it becomes skeletal. Many years later the mother dies, the father grows old and has to eventually leave his family home. He packs up his child's remains and personal effects in his old suitcase and intends to bury them somewhere special to him/them. For some reason, he cannot finish his last duty, and the suitcase ends up on the side of the road, forgotten for a short time until now.
I know this is even less likely than any other scenario, but it's a much nicer place then where the other possibilities are heading :/