On 19 July 2021, a thirteen-year old Secondary One male student named Ethan Hun Zhe Kai was struck to death with a combat fire fighting axe at River Valley High School in Boon Lay, Singapore, in an incident which was reportedly unprecedented in the history of Singapore. The killer was a sixteen-year-old Secondary Four male student, who was arrested for Ethan's murder shortly afterwards. The boy was initially charged with murdering Ethan; his charge was eventually reduced to manslaughter on the grounds of diminished responsibility, and he was thus sentenced to jail for 16 years on 1 December 2023.