austrailian movie: teach & kids on feild trip get kipnapped at a cave

[Count Floyd]

I saw it on cable a few years ago. A teacher and a group of kids are help at gunpoint by thugs and the teacher and some of the kids tries to escape through the cave. does this sound familiar? I think it was from the mid-late 80s.

[Mr. DS]

That would be Fortress
http://www.imdb.com/title/tt0091069

[Count Floyd]

ah, there it is! It was driving me crazy cuz I googled and imdb'ed but couldn't find nothin! Thanks so much!