Did I do something wrong?
No, you didn't do anything wrong. There are only a handful of things in the world that can justify a guy standing a girl up for anything.
1) He was killed. If he is still alive, chances are he's a punk.
2) He is really a superhero and was called away to stop a disaster. Did you happen to see any searchlights shining weird shapes onto clouds?
3) A family emergency (someone else died, fell deathly ill, voted for Nadir, etc.). But even then, it is good form to let you know somehow.
I suppose there might be a few other justifiable occurrences, like UFO abduction, that I have forgotten about, but no; when you get stood up, it is never anything you did, because nothing you could do could justify a guy behavior in such a poor manner. It is inexcusable.