What really destroyed the Maya civilization?

What really destroyed the Maya civilization?: "One of the biggest debates in archaeology is what destroyed the extensive, highly-advanced Maya civilization 1,000 years ago. It's known that the empire went through a long collapse from roughly 800 to 1,000, leaving behind a network of pyramids and monumental architecture in the Yucatán jungles. But why? We have only educated guesses, and one of the most widely-believed theories is that some kind of climate catastrophe drove the Maya to abandon their cities in droves."