One day, the Aztec god Quetzalcoatl appeared to a group of Aztec priests and told them that they must build a temple in his honor. The priests were overjoyed, and they set to work immediately. They built a great temple, and when it was finished, they invited Quetzalcoatl to come and see it. Quetzalcoatl was pleased with the temple, and he rewarded the priests by giving them a sign: he caused a great flood to come, which destroyed the city of Tula. Only the priests and their families were saved.