I seem to recollect somewhere in the back of my mind a short story about a knight who was getting ready to battle a dragon, and he got up, the dragon was getting closer, pulled out his sword and BAM! He got hit by a modern-day train that was the "dragon" in question.
Any ideas? I really need the title for this, but I'm not even sure this was Bradbury...

Yes, that is the Bradbury story "The Dragon." A few years later someone ripped off his idea in the story "The Lost Valley," which deals with Native Americans battling a train.

Thanks a million!

Finally I got an answer to that question!

You're a lifesaver