A sword-wielding man attacked students and teachers at a high school in Trollhättan, killing three people in Sweden's deadliest school attack. 2015 Trollhättan school attack: On 22 October 2015, a mass stabbing occurred at Kronan Primary School in Trollhättan, Sweden. 21-year-old Anton Lundin Pettersson killed three people and wounded another two with a sword, later dying from gunshot wounds sustained after charging police. October 22, 2015. Wiki link