I took the Bart in San Francisco every day for a decade, definitely saw some things. Saw a guy take a shit between the cars. Saw someone flip off the rails and kick someone in the head.

The one I remember the most was during a busy morning commute, I had my headphones on and I see this older guy pushing through people to follow this younger woman. She kept moving up and down the train to get away from him. After seeing this a few times, I stepped in front of him and told him "I don't know what's going on, but she clearly doesn't want to be near you, so you gotta leave her alone". He snapped at me screaming that it was his daughter and I need to stay the fuck out of their family situation. Myself and a few others blocked him, and he got off at the next stop. When I asked the woman if she was okay, she said she had no relation to the guy and had never seen him. Scary stuff all around. Im assuming he was mentally ill and had some previous drama about losing his daughter, and something triggered in his brain when he saw that woman. I thought for sure I was gonna get stabbed that day, and if the train wasn't so crowded I think things would've ended a lot differently.