Driver Nguyen Van Lam, 58, was arrested and prosecuted on May 31 for "unintentionally causing the death of other people".
The same day, Thai Binh Police also prosecuted two teachers, Doan Thi Nham, 58, and Nguyen Thi Phuong, 26, for "lack of responsibility causing serious consequences". The two teachers have also been banned from leaving their residence while local authorities are investigating the case.
Earlier on May 30, police also detained and prosecuted a carer Phuong Quynh Anh, 30, who the Hong Nhung 2 Preschool hired to pick up the children on the school bus for unintentionally causing the death of other people.
According to reports from the Vu Thu District Police Department, the boy Gia Huy was collected by Anh from his house at 6.20 am on May 29 and taken to Hong Nhung 2 Preschool with nine classmates.
After a five-kilometre trip, Anh took the children to their class, and the driver Nguyen Van Lam, 59, drove the 29-seat bus to the school's parking area and left.
Although Gia Huy sat on the seat right behind the driver's seat, he was left behind.
At class, the two teachers took a photo of the children to post on the school's website to check attendance. They noticed Gia Huy's absence but did not inform his family. It was not until 5 pm the same day that the boy's uncle came to pick him up, and the teachers replied that Gia Huy had not appeared at school that day. They then rushed to the bus and asked people to help break the door open to find the boy lying unconscious inside.
The boy was taken to Thai Binh Provincial General Hospital, where doctors said that he was already dead.
Initial investigations showed that the boy died from respiratory failure as he had been left inside a closed bus for over 11 hours in hot weather. Wednesday was particularly hot, and the temperature in Thai Binh Province was 36 degrees Celsius.
Hong Nhung 2 Preschool is a private school established in 2016. The school has two branches with some 400 students.
A six-year-old boy died in similar circumstances in Hanoi in 2019 after being left on a school bus. A carer and the driver were given jail sentences of 21 months and 10 months, respectively, for "accidentally causing death", and a teacher received a 12-month suspended sentence for "lack of responsibility causing serious consequences".