Robert Knox, an teenage actor who was to appear in the newest Harry Potter (Harry Potter and the Half-Blood Prince), was stabbed to death during a brawl early Saturday. Robert Knox was 18 years old. He is pictured at right with his mother and younger brother.

Robert Knox was involved in a fight outside of a London bar on Saturday — resulting in his stabbing and death. The rumor mill maintains that Robert Knox was defending his brother at the tiime of the incident.

Robert Knox will play Ravenclaw student Marcus Belby in Harry Potter And The Half-Blood Prince.

Including Robert Knox, five men were taken to hospitals following the fight and stabbing and one 21-year-old has reportedly been arrested on suspicion of murder.