Which episode was this?

So, I remember watching this show from my childhood, and I remember one particular episode that really freaked me out, but I only remember it vaguely. It was something like, one of the kids got stuck in this underground basement/garage type thing, and then there were people down there that said there's no escape from it or something and that they have been down there for a really long time or something like that. Does this ring a bell to anyone? I would like to know which episode it came from, if it does. I apologize for my bad explanation. Was this episode even real? I tried to find it, and I couldn't. Maybe this is just like Candle Cove.... Ah well, tell me what you think.