It is derived from the words:
* kata (κατά) meaning "down" or "according to"
* strophe (στροφή) meaning "turning" or "a turning point"
Therefore, "catastrophe" literally translates to "a turning down" or "a downward turn." It originally referred to a sudden and disastrous change in events, particularly in a play, but has since come to be used for any major disaster or misfortune.