Tran Manh Hung, 44, an employee in charge of materials for the cement mills at the cement factory, was arrested by provincial police on Tuesday for "violations against regulations of law on occupational safety, occupational hygiene, and safety in crowded areas."
Exactly what Hung did has not been announced.
Previously at 1:30 p.m. on Monday, 10 employees of the cement factory performed maintenance work on a cement mill. Three were outside the mill while seven were inside it.
During the maintenance, the mill suddenly operated. The three people on the roof were thrown to the ground, while the seven inside were all killed.
Nong Van Tuan, 29, a survivor, said he was injured in the leg and tried to reach the control room about 20 m to shut down the power source. There was no one inside the room at the time.
An initial investigation said the cause of the incident were due to issues with the mill's motor engine.