线程1:播放声音时，EXC_BAD_ACCESS(代码= 1，地址= 0x48)

每当我尝试将声音文件分配给变量时，我的应用程序就会崩溃.我已经仔细检查了我的声音文件名，但无法正常工作. 这是我的代码:

Whenever I try to assign a sound file to a variable my app crashes. I've double checked my sound file names, but I can't get it to work. Here is my code:

struct variables {

    static var randomCode = 0
    static var timerCounter = 30
    static var timer = Timer()
    static var explosion:AVAudioPlayer = AVAudioPlayer()
    static var defuseSound:AVAudioPlayer = AVAudioPlayer()
}



override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.

    //Error occurs on the following line
    let explosionFile = Bundle.main.path(forResource: "explosion", ofType: ".mp3") 
    let defuseFile = Bundle.main.path(forResource: "defused", ofType: ".mp3")

    do {
        try variables.explosion = AVAudioPlayer(contentsOf: URL(fileURLWithPath: explosionFile!))
        try variables.defuseSound = AVAudioPlayer(contentsOf: URL(fileURLWithPath: defuseFile!))
    } catch {
        print(error)
    }