Angst and tragedy are two different genres. I repeat, angst and tragedy are two different genres. Not because you killed main character, you can tag it as angst. Angst is some kind of emotion. Sadness. Pain. Despair. If you didn't convey any of these emotions BEFORE the tragic scenes happen AND end it right exactly at that tragic part, that's not angst, that's tragedy. Is tragedy all about death? NO. It can be about separation, destruction, or ... anything under the word "tragic."