Pham Minh Dang went to bathe in a pool that was 90 cm deep Hai Thuong ecotourism site in Huong Son District. Some 30 minutes afterwards, security guards saw Dang floating on the surface of the water with dozens of other people swimming around him.
Lifeguards tried to resuscitate him, but Dang was already dead.
Nguyen Xuan Loi, director of the Quy Gia company, which operates the tourism site, said initial forensic studies by authorities determined that the boy suffocated "likely due to health issues, not drowning."
Loi said the site has three pools for different age groups, and seven employees monitors.
Dang was at a pool for teenagers.
When lifeguards performed first-aid on him, "there was no water inside his lungs," Loi said.
A representative of Son Trung Commune said a police investigation is ongoing to figure out the boy's cause of death.
The Hai Thuong ecotourism site, spanning over 20 ha, is a popular tourism site in Huong Son District with hotels and attractions.
Over 1,400 cases of drowning were recorded in Vietnam in the 2020-2021 period, according to data from the firefighting and rescue police department.