The rise of the Mycenaean civilization is a presumable cause, as traces are found of strong Mycenaean influence in the ruling structure of Cnossus at that time (most notably the use of Linear B, an early form of the Greek writing).
Bouchard, Elsa. "Collapse of the Minoan civilization". The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=11120, accessed 21 May 2013.]