After the district police wrapped up their investigations into the boy’s death Friday, they recommended that the driver, the bus monitor and the homeroom teacher be charged with involuntary manslaughter and negligence.

The involuntary manslaughter charge would apply to Doan Quy Phien, the driver, and Nguyen Bich Quy, the bus monitor. Nguyen Thi Thuy, the homeroom teacher, would be charged with negligence causing serious consequences.

No managers of Gateway, the school in which the boy studied, has been held responsible.

The boy, Le Hoang Long, was picked up by the school bus at 7 a.m. on August 6. It was Long's second day at school.

At 8 a.m., after arriving at school, bus monitor Quy allegedly let the students down without checking their number, and falsely recorded that all 13 students had left the bus. Then, driver Phien drove the bus to a parking lot, and allegedly locked the bus without checking whether any student was left inside.

At 3:45 p.m., after the bus was driven back to the school to take students home, Quy discovered Long lying motionless on the bus floor behind the driver's seat. He was pronounced dead at the hospital. His death was caused by "heat stroke" and "respiratory failure" and no influence of external forces or diseases was seen, a forensic report said.

The police allege that the homeroom teacher, Nguyen Thi Thuy, did not report Long's absence to the family, as per standard school procedures, which include writing the absent student's name on the corner of the board and sending messages through the school's student management applications. After being reminded by colleagues, Thuy reported Long's absence. However, her report claimed that the parents were aware of it.

The next day, Thuy allegedly asked school staff to change the report about Long to absence without parents' notice.

Thuy's inattentiveness and lack of responsibility in students' management contributed directly to the belated discovery of Long, police said.

Duong Thi Hoai Anh, the Gateway school principal, was not held responsible because she was on sick leave the day it happened.