A few little mistakes and thousands died. We are currently watching Japan to see if they can fix their reactor, but we gloss over a history of industrial accidents. Boston once was flooded by hot molasses that killed horses and men. Dam breaks have killed hundred of thousands of people. We don't want to think about how death might be just a block away.
Unstoppable is about a train that gets away from its conductor (played with amusing reality by the guy who plays the idiot brother in "My Name Is Earl"). The train is loaded with dangerous chemicals and gaining speed. Can anyone stop this train before it blows up in someone's backyard? Well two train employees, a newbie and an old hand, think they can.
This is an exciting film and has a nice feeel of reality. Is it surprising? Not so much. You know how the characters are going to act, and you are pretty certain what actions will result in mishap or victory. Somehow, though, that doesn't take away from the fun. This is a good old fashioned movie in all the right ways.