A sugar factory in the central province of Nghe An on Monday said three people died when they fell into a wastewater treatment trench on site.
The accident happened on Friday when worker Le Van Dung, 25, slipped and fell into the trench, according to a representative from Song Lam Sugar Factory in Anh Son District.
Another worker, 22-year-old Nguyen Xuan Thuyen, then jumped in to rescue Dung, but they both soon lost consciousness due to difficulties in breathing because of the gases in the trench, the representative said.
Nguyen Van Hung, a 53-year-old expert from the Vietnamese Institute of Chemistry, who was working nearby also jumped in to rescue the victims together with another worker named Trung.
But, they soon fainted.
They were later pulled out with ropes, but Dung and Thuyen had already died, while Hung and Trung were rushed to Nghe An General Hospital, where Hung died. Trung is still undergoing treatment at the hospital.