An express bus overturned Monday on Malaysia's main highway, killing at least 19 passengers in one of the worst traffic accidents in the country's history, police and fire officials said. The 10 other people on the bus, including the seriously hurt driver, were hospitalized with various injuries, said a hospital spokesman and a police officer contacted at the scene in Bukit Gantang, about 200 kilometers (125 miles) north of Kuala Lumpur. Two Indonesians were among the dead, while the others were all Malaysian, said a spokesman for the fire station in the nearby town of Taiping. «From our investigation of the brake marks, the driver was sleeping,» said the spokesman, who also declined to be named for the same reason. National news agency Bernama reported that seven of the injured were in serious condition. The accident occurred before dawn on the North-South Expressway, which runs 880 kilometers (550 miles), the entire length of the country from the Thai border in the north to Johor Bahru at the southern tip of the Malaysian peninsula. Bernama said the bus, traveling from Johor Bahru to the northern town of Alor Star, was going downhill when it hit the curb and careened 20 meters (yards) off the road before flipping over. It had completed about 650 (405 miles) kilometers of the 830-kilometer (515-mile) journey when the tragedy occurred. Many passengers were flung out of the bus through the exposed roof and others died inside when the sides of the vehicle were crushed on impact, Bernama said, citing police.