In 100 AG, the canyon guide was asked to escort two feuding tribes across the canyon. When he arrived, both tribes began to argue about who would travel the canyon first. The Zhangs claimed that they should be first as they had sick people, while the Gan Jins retorted that they should go because many of their tribe's members were elderly. Aang finally reached a compromise by suggesting that Appa carry each tribe's sick and elderly across while the others traveled together across the canyon on foot. Before embarking on the journey, the guide warned them not to take any food into the canyon, as it would attract dangerous predators. Catastrophe struck, however, when a canyon crawler attacked shortly after he had broken a rock shelf so potential Fire Nation soldiers could not follow them. Aang