my app keeps crashing i am not sure why

class playlistMasterViewController: UIViewController {

    @IBOutlet weak var playlistImageView0: UIImageView!

    override func viewDidLoad() {

    super.viewDidLoad()



        let playlist = Playlist(index: 0)
        playlistImageView0.image = playlist.icon


    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "showPlaylistDetailSegue" {
            let playlistDetailController = segue.destinationViewController as!
            playlistDetailViewController
              playlistDetailController.playlist = Playlist(index: 0)



        }
    }



    @IBAction func showPlaylistDetail(sender: AnyObject) {

      performSegueWithIdentifier("showPlaylistDetailSegue", sender: sender)


    }



}