German film or series between 1982 and 1989?

Hello everyone,

I'm looking for a German-language film or series that was shown on German television in the 80s, i.e. ARD or ZDF. It could also have been a dubbed series/film from abroad. The film was shown at lunchtime/afternoon, so it was more on children's television. It's about a boy who hasn't spoken/can speak since he lost his parents in an accident. They were driving in a car that was hit by a train. The boy was probably in the car. The lights of the approaching train are striking and appear several times in dream-like sequences. The boy has a suitcase (toy suitcase?) full of ballast stones, exactly the kind of black, jagged stones used on railway lines. He always has the suitcase with him and doesn't let go of it. During a scuffle over the suitcase, which he doesn't want to let go of, the suitcase bursts open and the stones come out.