The scene I remember has a man traveling with two children who are alone in the world. The boy has a necklace from his mother. While playing in the water of a river, the boy gets swept over a waterfall. The man jumps into the pool below to save him, but come up only with the boy’s necklace. He recognizes it and asks the other child, “what was your mother’s name???” I think he is their father, but he left their mother when they were tiny? The boy who went over the falls end up in a cave behind.
That’s all I can remember.
I would have seen this on TV in the early to mid-90s, it was in English and color. It could have been on the Disney Channel, as I had a subscription around that time, but it’s possible it wasn’t.