@Strannger18 said:

Could someone please confirm for me what happened? Her father committed suicide. That much I'm clear on. She thinks it's her fault because, "There was this room I wasn't allowed to go in..." And he slipped on a tambourine.

He was shooting heroin or something from what I could tell, and she was not supposed to go in the room and see it. That's why she wasn't allowed in that room.

I suppose her dad was so ashamed that she saw him in the act of shooting up, that he ran out of the house and shot himself. I couldn't quite understand how the tambourine factored in though. Perhaps it was just a memory of an object that was there at the time, a reminder.

Also, maybe he was so high on drugs or in an altered mental state that he killed himself from that? It could also be suicide/drug abuse due to PTSD, as he was shown to be back home from previous military service.