AVFoundationでのBGMの再生について(Swift)

import UIKit
import AVFoundation

class ViewController: UIViewController, AVAudioPlayerDelegate {
    var audioPlayer:AVAudioPlayer!
    @IBOutlet var button:UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()
        let audioPath = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("sample", ofType: "mp3")!)
        //audioPlayer = AVAudioPlayer(contentsOfURL:audioPath)
        audioPlayer.delegate = self
        audioPlayer.prepareToPlay()

    }

    @IBAction func buttonTapped(sender : AnyObject) {
        if ( audioPlayer.playing ){
            audioPlayer.stop()
            button.setTitle("Stop", forState: UIControlState.Normal)
        }
        else{
            audioPlayer.play()
            button.setTitle("Play", forState: UIControlState.Normal)
        }
    }
}

コメントアウトの部分で「Call can throw, but it is not marked with 'try' and the error is not handled」というエラーが出てしまいます。どなたか解決方法をお教えください。