I remember when something in /r/WTF. There was a story about a guy that got crushed in the exact circumstances as this post. This story stuck with me long after reading it.
When I went to work for a steel company in the mid 90's we got the lesson of not messing with train cars from an old timer that had been at the mill for decades.
He had pictures and a story. The guy that had gotten coupled, stuck in the couplers of two connecting train cars, asked that pictures be taken and his mistake be used as an example for future workers. So the old timer had some pretty intense pictures.
The first thing they do is set up a tent around you. Not a big tent, but enough to give you privacy, because as soon as those cars are uncoupled, you're dead. They tarp off the bottom of the coupler, so that you don't get the image that you're talking to just a torso. They ask who you want to see before you die, if you have a wife, a priest, co-workers or anyone else that you want to say your last words to. They also get a doctor on-site to administer drugs and final care to you. All of this happens very quickly, because you don't have a ton of time, but it is a slow death.
The old timer had pictures of the guy coupled, the tent being set up, the coupler being tarped, pictures of the wife entering in tears, pictures of the wife leaving in tears and pictures of what happened after the guy was uncoupled. The one that got me was the picture of his kids talking to him through the tent side, he wanted to tell his kids he loved them one last time, but didn't want them to see him in that condition.
It is not a user friendly experience. This guy got caught between the couplers because he thought he could beat a slow moving train car and against one of the train-worker's warnings, he gave it a shot anyway. He lost. When backing up a train with multiple cars, the cars can gain or lose speed quickly because couplers are not a rigid connection. It just so happened that he got in the middle just as the cars picked up a bit of speed, he hesitated and that was that.
After you say your goodbyes, and in this instance, the doctor loaded the guy up with a bunch of morphine (or pain killers) and they uncoupled the train, at which point every internal organ that was where it was supposed to be when the train was coupled, slid out and onto the ground and half a torso dropped out.
The old timer had pictures of it all, and during this class, everyone was either white as a ghost or dry heaving. It was silent and everyone was just listening to this older guy talk about losing his friend.
The class did it's job. I'd hear the train bells and immediately be aware of where the train was, what it was doing and what my proximity was to train tracks. Even to this day, I give trains plenty of respect and the sounds of train bells make a shiver run up my spine. Even though everyone went through this class, someone still got coupled in the time that I was working there. I didn't see anything but the white tent, but knew exactly what was going on.
Working in a steel mill made me also realize that everything in a steel mill can maim or kill you almost instantly. The mills themselves, the furnaces, the trains, the coiled steel, the slabs, the overhead gantries, none of them care about you. If you're in the wrong place at the wrong time, they'll just continue doing what they're supposed to do, they'll just maul you in the process.
Source: https://www.reddit.com/r/WTF/comments/1og5g4/man_hit_by_a_train/ccru6u7