1980's or 1990's futuristic movie
Ok, I need help finding a movie that I haven't seen in like 12 years but I would love to find it. It's starts in this poor city with a lot of rugged looking people. And there are these kids who are visiting with some old guy, like a professor or something. And while they're there, these police come and start arresting some of the people. But the kids find a way to get out and find a safe place. I remember the journey being in the dessert, and then this big bald buy helps them and ends up giving up his life for these kids and the girl cries for him. It used to be one of my favorite movies as a kid but I just can't remember what it's called. Thanks in advance if anybody's able to help me out :)