(TW: death, suicide) Death or storm?

Did Bua die in the beginning or did the storm actually take her back to the past?

I think it could be possible that she could have ended her own life in the beginning because of the statement her friend made about her being happy at the end, how unhappy she was in the future, and her decision to stay in the past. But, it could have really just been the storm that took her away and the drama isn't implying anything else. Did anyone else have the same thoughts as me?