How can I edit the animation I just created in Unity 5

So I was following Brackeys's survival game tutorial series and I created an attack animation for a katana. I guess I "created" the animation too soon, because I was suppose to add an event into that attack animation. Now when I open my "Animation" window it just looks like this

As you can see the animation I would like to edit is called "attackkatana" and it's no longer available in the animation window. How can I edit the animation or is it even possible?

Thanks in advance.