Another natural disaster occurred in 1 A.D., the eruption of the volcano Popocatépetl caused the population of capital cities liked Chacaltzingo, Atlantepec, Cuajimalpa, Amaluacan, etc. to move to other capitals such as Cholula, Totimehuacan, and Teotihuacán. Thus those capitals became megalopolis which had an exponential growth in economy and culture.