On September 16, more than 100 students at Dongdaihe Zhizhen Middle School in Huludao City, Liaoning Province, experienced symptoms such as nausea and vomiting after having meals at the school, and dozens were sent to the hospital. On September 17, the food safety office of Suizhong County reported that it was caused by improper processing in the cafeteria leading to acute gastroenteritis, and some students remained in the hospital for observation.