1. The tragic flaw that inevitably leads to the downfall of a person or enterprise.
EX. The hamartia of the RMS Titanic, in a cosmic sense, was to declare the ship "unsinkable". In Greek tragedy, such hubris tempts the gods to intervene in order to teach the mortals a lesson in humility. And yet, in a tragedy of such titanic proportion, the causes of the outcome are not as simple as the tempestuous whims of some envious deity; the ship wasn't constructed well enough, the crew did not see the iceberg until it was too late, the passengers were packed away improperly and there were too many souls on boards and too few lifeboats, and so on and so forth, until all of the variables added up to a formula for disaster. It is unlikely that we will ever know why such a foul fate befell the ship on its maiden voyage, but we can learn from the mistakes identified.
And then there are the various craptastic unofficial software made to ride the coat tails of James Cameron's mega-successful Titanic film; their tragedy is that somebody thought they could make a fun game based on a romantic disaster film based on a real-life tragedy. I dunno if the gods came together to punish those game designers, but it is a comforting thought to imagine their wrath coming down upon their heads.