Let me tell you a story.
On June 22, 2008, I was riding the Lake Shore Limited from NYP to CHI. Somewhere in upstate New York, around 11:30 pm, we made a scheduled station stop. It was getting late and I had to call my dad about my ride the following day, and didn't want to disturb the other coach passengers with my phone call. So I was going to head to the lounge, right after this station stop, which was going to cause some noise and commotion anyway. I waited for the boarding passengers to find their seats, settle in and clear the aisle, and then got up and started walking forward on the train for the lounge. The train was back up to speed. I was dressed for bed (or sleep anyway, this is coach) and grabbed my phone, and left my eyeglasses.
It was a vestibule just before entering the lounge car. It's not clear to me now whether it was the rear vestibule of the lounge car (is there one?) or the forward vestibule of the last coach car. But as I walked through it looked like the train door was open on my left. I stopped and looked. I could see no door, and I could see the ground rushing by at 60 MPH at the bottom of stairs for boarding. I must have stood there for 10 seconds looking because I couldn't believe the door could have been left open, and also wasn't wearing my glasses. I considered whether my eyes were lying to me, but I decided that no, Amtrak didn't recently switch to all-glass doors, and yes, that definitely was the track bed rushing by at the bottom of the stairs, and yes, by the sound of the rush of air as well the door was definitely open. I then went on walking. I took my next step in a deliberate manner, having considered that continuing forward towards the lounge was safe, but taking my next step to my left would put me on the steps, and if I tripped on those I was through.
I walked into the lounge and facing me at the other end of the car was a middle aged guy with an Amtrak uniform sitting at one of the tables. I politely asked whether he was part of the train crew. He kind of snorted an affirmative answer, gesturing to his uniform. I said "I think you have a door open back there" and gestured back and beckoned as if he could follow me. Without a word, he hauled himself out of the booth, walked past me and continued out of sight into the vestibule. Several seconds later I heard a door slam shut. He reappeared and walked by me without any comment. I sat down, made my phone call, then went back to my seat and off to sleep.