On the news, I saw the pic of the train with the tractor tires. I was wondering what kind of tractor it was.

Can someone help explain what I/We are looking at? 

There is a small pic with 3 fire dept volunteers in it. It looks like the engine of the train is in that pic. Is that correct? 

So, did the tractor collide with the rear of the train?  Was this train going in reverse?  

Can someone explain?