The accident took place about 10am as the truck was heading towards the 7th Motorway’s 39th kilometre marker in Tambon Bang Samak.

Truck driver Thongchai Somwang, 26, sustained a forehead wound and bruises while his newly recruited truck conductor, Phutthasit Srisuk, 26, died from a broken neck after he flew out of the vehicle on impact as the falling truck crashed into a concrete barrier.

Their colleague Saranyu Sramul, 25, said Thongchai had been with the company for a few months while Phutthasit had just started work for the first time on Sunday.

They were transporting fertiliser from Laem Chabang Port to a warehouse in Bangkok’s Lat Krabang district. The uphill curve had been the scene of many accidents because the weight of heavily-loaded trucks would shift suddenly, Saranyu said. He said a truck must be driven at sufficient speed to go uphill but not too fast as to lose control.

Motorway rescue worker Kampol Poungkaew, 32, said that, in the three years he had worked in this area, there had been four crashes involving container-transporting trailer trucks at this spot during his shifts.