Maybe there'll be another try with better luck. Endurance swimmer Diana Nyad had to quit her 103-mile swim from Cuba to Florida Sunday because of painful jellyfish stings, her spokeswoman said. It was her second attempt at the feat. Nyad was more than halfway there after she pushed through the tough second night of her marathon swim. The 62-year-old swimmer was stung by a man o' war jellyfish at the start of her journey.