fine in belgium

Returning to Brussels from a conference in Mons, Belgium, I was running frantically in order to catch the last train. I took a few wrong turns, then came to the station. After trying all the locked doors, I ran around the side, saw my train, barreled through the underpass and back up, and lunged for the door as I heard a woman yell wait, forced it open and got in. The woman kept on yelling, though, and eventually I exited the train to go up to her. She was the conductor, and very angry at me. We got on the train, through the non-closed door that she had (apparently) been telling me to go to, and she fined me 15.80 euro for boarding the train after the signal for depart. A Belgian colleague told me the next day that someone had boarded like this, then got into an fight with the conductor, and either fallen off the train or thrown the conductor off, and someone lost a limb, so they're very serious about this offense now. It wasn't clear to me how cracking down on this would help the limb-loss, but there you are.