Did this ancient site experience a catastrophic end?

Tiwanaku, or Tiahuanaco in Spanish, is a ruined citadel occupying almost 10 square kilometers in the Bolivian Andes at an altitude greater than 3800 meters. Carbon-14 dating methods suggest that the site is no more than 3700 years old. However, as previous Picture of the Day articles discuss, radiometric dating is, at best, an unreliable system for establishing age.

According to the book, Tiahuanaco, The Cradle of American Man by University of La Paz Professor Arthur Posnansky, Tiwanaku is closer to 17,000 years old, perhaps one of the oldest surviving human habitations on Earth.

Posnansky based his estimate on the alignment of the Kalasasaya temple stones. “Kalasasaya” means “standing stones” and refers to the large stone pylons apparently aligned deliberately around a central courtyard. The current temple is a reconstruction and does not reflect the original architecture that the pre-Incan inhabitants intended. There was no wall between the standing stones as there is today..........................