Their destruction is part of the myth of Huitzilopochtli's birth. One day Huitzilopochtli's mother Coatlicue is sweeping the temple where she serves. When Coyolxauhqui and the Centzon Totochtin hear about this, they are livid, and attack and prepare to decapitate her. Just prior to or at the moment Coatlicue is decapitated, Huitzilopochtli leaps fully armed out of her womb, cuts off Coyolxauhqui's head, and throws her off the temple. The Centzon Totochtin try to escape, but Huitzilopochtli either rips out their hearts, decapitates them, throws them off the temple, or stabs them. Copil's heart is thrown onto the island where Tenochtitlan was to be founded.
Aztec priests used this myth to try to justify their ritual of human sacrifice.
Clavigero, Francesco Saverio (1807) . The history of Mexico. Collected from Spanish and Mexican historians, from manuscripts, and ancient paintings of the Indians. Illustrated by charts, and other copper plates. To which are added, critical dissertations on the land, the animals, and inhabitants of Mexico, 2 vols. Translated from the original Italian, by Charles Cullen, Esq. (2nd ed.). London: J. Johnson. OCLC54014738.