Disappearance theories of the Chichen People

The Disappearance

By the time the Spanish conquistadors arrived, Chichen Itza had been abandoned. The Spanish found newly inhabited areas, formed by tribes that had returned from their former exodus into Guatemala. This poses the question: what happened to the people of Chichen Itza? The answer to the mysterious disappearance of Chichen Itza's inhabitants remains unknown, though it is believed that the city's abandonment occurred towards the end of the 13th century. Four possible theories have emerged to as what may have happened:

1. The devastating war that involved the three more powerful cities on the peninsula: Chichen Itza, Mayapan and Uxmal. The last two allied themselves to defeat Chichen, but there remains the question: Why didn't they occupy the conquered dominion?
2. Possibly a long drought... For any other place this may be possible, but the Yucatan peninsula is riddled with drinking water from sinkholes (cenotes) connected by underground rivers, so... a drought?
3. Perhaps a locust infestation which consumed the food source?
4. Here is an interesting theory: from the very early days of the Toltecs´ arrival in the 10th century, human sacrifices became part of everyday life and the Sacred Cenote (water-filled sinkhole) became the resting place for thousands of bodies over a 300 year period. This may have resulted in the pollution of the water table and caused a deathly epidemic. Therefore, the population may have died-out from a cholera-like ailment.