BEIJING - A Siberian tiger at a wildlife park near here attacked and killed a man who climbed into its enclosure thinking he found a shortcut down from the Great Wall, officials said today. The 20-year-old man, whose last name was Guo, was hiking with two other people when the group decided to jump down to save time - unknowingly landing themselves in Badaling Wildlife World's tiger enclosure. The tiger pounced on the victim, knocking him down and clamping its jaws around his throat, killing him