The 10th grader was drinking water at a hot and cold water dispenser after playing sports at Ngo Thoi Nhiem private school on Tuesday when he got an electric shock and became unconscious.
The school sent him to a hospital but he did not survive.
The authorities in Phuoc Long A Ward of Thu Duc City, where the school is located, said on Thursday it is possible that there was a power leakage at the drinking water system.
Thu Duc City police are looking into the case.
Ngo Thoi Nhiem private school currently has 8,500 students from kindergartens to high school level.