The landslide occurred on Sunday in the southern city of Shenzhen, smashing into Hengtaiyu industrial park in Guangming New District. Thirty-three buildings were buried, and at least 85 people are still missing in China's latest industrial disaster.

The landslide covers an area of 380,000 square meters with silt 10 meters deep, according to state news agency Xinhua. No deaths have been reported so far.

Some people had to stay in emergency accommodation

The buried buildings include factories, office buildings, dormitories and low-rise buildings. A section of the major West-East Gas Pipeline, owned by China's oil and natural gas producer PetroChina, exploded after the landslide, said Xinhua.

A man-made disaster

China's Ministry of Land and Natural Resources said in a post on its official social media account on Weibo that the accident was caused by the collapse of a mountain of waste soil. It had been stacked too steeply and this resulted in instability.

The pile of construction waste had been stored at an old, disused quarry. The quarry was authorized as a temporary construction soil dumpsite from February 2014 onwards, but only for a year. The site should have stopped operating last February, according to the Chinese newspaper National Business Daily.

However, workers in the industrial estate said that the waste dumping never stopped. They also complained about the pollution and safety problems caused at the site.

Citing workers in the industrial estate, the National Business Daily also reported that trucks transporting waste from nearby construction sites had come every day for the past two years.

The landslide leaves authorities seeking a dump site for tons more soil

Problem reported a year ago

Rapid development in the city, with increasing construction of new buildings and subway lines, has created a large amount of construction mud waste. Shenzhen lacks the capacity to accommodate all of the waste. A local state-run newspaper, the Shenzhen Evening Post, pointed out a year ago that the nine existing dump sites were far from enough.

"It will lead to two possible consequences: unregulated dumping activities and illegal dumping sites," the newspaper had warned in October 2014. The same report noted that authorities had been struggling to find space for construction soil waste since 2006.

Prime Minister Li Keqiang has ordered a public investigation into Sunday's landslide.