By Surasak Rimseub
Deputy inspector Pol Lieutenant Suksan Passawakang said officers and rescue workers were on the scene soon after 1.30am.
The Din intersection in Tambon Phosa, Muang Ang Thong, has a single traffic light blinking at night for vehicles approaching from all directions.
The truck was heavily damaged in front. The Toyota Vios sedan, which also struck a roadside power pole, was wrecked.
Sutthipong Phipak, 40, the car driver, and Napapan Phongkham, 27, were severely injured and taken to hospital, where Napapan was pronounced dead.
Truck driver Nikhom Kwanyeun, 32, told police he was hauling rice to a factory and slowed when he saw the sedan approaching but could not avoid the collision.
Police were investigating further to see if charges were warranted.