I too fell once in a tub, although I started out in it, so the fall was a bit different. It was 1985, and I was showering in a hotel room in England, probably a day or two before I ran the South Downs Way run with Fanatic (although he wasn't called that then). A very narrow tub with a particularly slick surface. I moved suddenly at an unexpected change in water temperature and down I went. A bit painful and scary initially, but I was more or less ok, and emerged with a greater respect for tubs.