The truck, which was carrying agricultural products, was travelling from Kon Tum Province in the Central Highlands to Hanoi with three men on board: driver Le Dinh Quan, 31, Nguyen Van Hoang, 34, and Le Trong Tuan, 40.
When the vehicle reached a turn while driving through Quang Nam, the driver lost control, causing the truck to hit a highway barrier and flip over. The cabin of the truck slammed into the embankment of a mountain slope, killing all three people inside.
It took until noon for rescuers to get the three bodies out of the truck.
Police are investigating the accident.