I can only remember a bit of this film and it is driving me mad. I believe it was a 1980s made for tv children’s film, but it could be a regular movie or even part of a tv series. There are two children who discover a skeleton in a pit in the basement of an old house. It turns out a family lived there in the 1800s and a group of bandits broke in. The family was huddled by the fireplace in fear. When the bandits weren’t looking, the little daughter slips through a hole in the fireplace to the large basement area. The family is killed and a bandit chases the girl through the basement. As it is dark, the girl falls in a hole and dies. I believe the premise was the modern children figuring out the mystery of who the girl is and what happened in the house.