"How would you feel if one or both of your parents died?"
... I don't know.
Obviously, I would be sad, but ... death is one of those things the living can't understand, because it's not something you can experience and come back to talk about. I don't care how many people read the book or saw the movie "Heaven is for Real", or any of those other books and movies you see about people dying and coming back and "remembering their near death experience." You were dreaming, possibly hallucinating; move on. Stop trying to profit from other peoples misery. Stop trying to justify death, especially when it comes to kids, because there is no justifying that, ever.
I think if it were sudden, I would feel shocked. That's a pretty normal reaction, when it happens out of no where. Then I would feel angry and cheated out of the years I didn't get to spend with them. Then I would regret not spending enough time with them. Sadness would overcome me for along time. I'd cry a lot. I'd talk to them, even though they wouldn't physically be there. I'd write... maybe. I'd drink... a lot. I would probably have some kind of family get together, and talk about all the good times I had with them and all the happy memories, and maybe that might help me ease into acceptance.
If it were something that was a long time coming, a struggle with some sort of illness, and we were more prepared, I think it might be a little easier, because I'd be able to spend time with them and help them do the things they've always wanted to do before it's too late. I'd be able to tell them how much I love them, and say goodbye.
I think the only thing worse than losing is parent is losing a child. And even though I write all of this thinking "This is how I would probably feel," I cannot tell you for a fact how I would feel, because it's not something I have experienced, and I hope I never have to for a long time.
I can only imagine what it must feel like, and I am truly sorry to anyone who has gone through it.