From March 1 to 2, 168 grade 9 students, including: 9A1, 9A2, 9A3, 9A4, 9A5, Nguyen Trai Secondary School, Chieng Le Ward, Son La City, visited and experienced some locations in Moc Chau Town.
The journey ended after lunch on February 2 at Thao Nguyen Resort Moc Chau. After that, the students got on the bus and moved to Son La City. By the evening of the same day, more than 100 students were vomiting, nauseous, headache, diarrhea, fatigue... By March 3 - 4, dozens of students were still tired, dizzy, and had headaches, so they had to stay home from school.
Regarding this issue, on March 5, Mr. Tran Cong Chinh - Vice Chairman of Son La City People's Committee signed a document requesting the Department of Education and Training to urgently and seriously conduct an inspection and clarify the case of more than 100 students suspected of food poisoning after the picnicking trip.

The People's Committee of Son La City requests to determine the causes and responsibilities of relevant organizations, units and individuals and propose solutions for the incident; proactively contact the Department of Food Safety and Hygiene of Son La Province and the City Medical Center for guidance and advice on expertise and profession in handling the incident.
The People's Committee of Son La City also directs school units in the area to implement extracurricular and picnicking programs for students to ensure safety, according to the provisions of law; continue to direct the strengthening of food hygiene and safety in schools, especially boarding schools.