How do I get access to a train for my video?

I am a young filmmaker and I usually get forced to write my scripts around the resources that are available to me and I am starting to change that but here's my problem. I wrote a script that must become a polished video by Sunday, and for the most part that would be easy, but there is a scene where a dog stops at a railroad track, and waits until a train pes by. Furthermore, a boy inside the train must tell the conductor to stop the train so him and his family can get out and retrieve their lost dog. How on earth am I supposed to film that?? I don't know the first thing about getting access to trains!!