At least 19 people died Tuesday, when a bus collided into a truck and burst into flames in central Thailand. The accident took place at around 4 a.m. local time when the Bangkok-bound chartered bus was hit head on by the truck, which had swerved into its lane on a highway in Saraburi Province, Thai Police Lt. Assawathep Chantanari told CNN from the scene. According to police, the truck driver was on his way to a rock-mining factory when he dozed off at the wheel and lost control of the vehicle. The truck veered over to the oncoming lane and straight into the path of oncoming traffic. Police said most of the passengers were trapped on the bus as it burned, with the driver and a three-year-old child among the fatalities. The driver of the truck survived and has been admitted to nearby hospital under police supervision. Twenty other passengers are being treated for their injuries.