Four died and three were injured after a pileup involving three trucks and a sedan in southwest China's Guizhou Province early Sunday, Xinhua quoted firefighters as saying. The collisions occurred at around 3:15 a.m. on the Yangtiao No.3 Bridge in Majiang County of the expressway linking Majiang to Kaili City, the Majiang county firefighters said. The injured were sent to hospital. The cause of the accident is being investigated.