cnn.com — San Francisco Zoo Director Manuel A. Mollinedo acknowledged that the wall around the animal's pen was just 12½ feet high, after previously saying it was 18 feet. According to the Association of Zoos & Aquariums, the walls around a tiger exhibit should be at least 16.4 feet high. Vid of tiger jumping 12ft. http://youtube.com/watch?v=1LjG7S8aqJg