Rob Knox, the 18-year-old actor who will appear as Marcus Belby in "Harry Potter and the Half-Blood Prince," was fatally stabbed outside a bar in Southwest London on Saturday night.
According to The Hollywood Reporter, Knox got caught up in a brawl that sent five young men to the hospital, including a 21-year-old who has been arrested on suspicion of murder.
His character is a Ravenclaw who is interviewed for Professor Slughorn's exclusive group of students in the sixth book, but Belby never plays a significant role in the series. Principal photography has already wrapped on the production.
According to the Times Online, Knox was protecting his younger brother from a man wielding two knives. Though this killing was not gang-related, teenagers in London are apparently being stabbed at alarming rates.