Public transportation #7 Underground #4 (sh)it happens

One day last week tried my luck to sit down on a crowded train when someone stood up. Unfortunately as I was leaning against the door (not the sliding one) I managed to get my bag strap caught by the handle. So by the time I freed myself, though it didn't take more than a few seconds, the seat was taken. Then I hurried, or rather pushed my way, over to another place that had just got empty, and took it. At the very same moment a strong, sour, unpleasant smell made me about to throw up. Next to me where someone had also just left, was an assful of puddle... something of a yellowish brown color. I was about to get up again, but someone suddenly sat there, and covered out the smell, too. Then it was too late to warn.