At around 2:10 a.m., Quach Dinh Trong, 57, the contract driver of a 16-seat bus carrying 16 people, was driving the vehicle on National Highway 1A when it crashed into a tow truck driven by Nguyen Van Tuan, 28, in Lang Son's Huu Lung District.
The tow truck was parked on the same side of the road the bus was driving on.
Following the initial impact, the bus then collided with another tow truck that was being driven in the other direction by Nguyen Thanh Bao, 27.
The crash killed four people on the bus immediately, while another died at a medical facility. Four others were taken to the Huu Lung District medical center, one of them being severely injured. Seven others were kept for monitoring at the Chi Lang District medical center.
The traffic police department reported that the bus was traveling on a steep road section with no street lights. The department posited that poor visibility could have caused the bus to crash into the parked vehicle. The parked vehicle had placed a warning object 16 m in front of it.
On-site testing revealed that all three drivers had no alcohol or drugs in their systems at the time of the wreck.