The Playhouse in the Woods

There's and old legend saying that two little kids, one boy, one girl, lived in a village surrounding the forest. Someone had built an old playhouse far out in the woods for the children to play and have fun there during the summers, weekend picnics, or even to just have fun any day. Everyday the children would go there even if there mother told them not to go. But one day, not listening to there mother wasn't such a very good choice...Now it's said that the children haunt the playhouse, and reports of the swings still moving have been made. Can you figure out what happened to the kids?