I'm looking for a sad song by a female vocalist about someone dying... (?)?

All I can remember of it is the video. The video is based around a girl called Angela who suffers abuse, until one day she's murdered by her parents, and the little boy, her best friend. that lives next door to her is too late to stop it (?). It's sung by this female vocalist who pops up at random occasions to sing the song and play the piano.