Nineteen people have died after a slice of a mountainside highway collapsed in China's Guangdong province, following days of heavy rain. Thirty others were taken to hospital after a 17.9m (58 feet) stretch of the Meilong expressway crumbled at 02:10 local time (19:10 BST) on Wednesday. Authorities have yet to state the cause of the incident. Images on state media showed a massive gash in the forested mountainside below the highway. The 30 people in hospital are "not currently at risk", state media report. The provincial government has dispatched 500 emergency response personnel to the scene. Footage that appeared to have been taken shortly after the collapse showed flames and black smoke billowing from below the highway. Another video carried by state media showed a smoking pile of charred cars partially covered in mud. Guangdong, China's most populous province, was hit with flash floods last week that killed four people and displaced 110,000 others. The floods also damaged dozens of houses, shut schools and caused flight cancellations and delays. Authorities have estimated economic losses of 140.6m yuan ($19.4m; £15.5m). The wild weather continued over the weekend, when a tornado ravaged a factory district in the provincial capital of Guangzhou, killing five people and wounding 33 others. Hailstones the size of golf balls were also seen raining down on the city.