Near the end of October, the cold air descended south to Renshou, Sichuan, and the county had a light rain. Huang Tao (pseudonym), a teacher at Renshou Chengbei Experimental Junior Middle School, returned to the classroom to accompany the students to study after lunch. At 12:21, he came in through the back door, and reopened the umbrella in his hand. He planned to hang it on the open space. When he bent down, Yan Mo, a 15-year-old student, rushed in, holding a brick in his hands. Hit his head.