Eight people were killed and three were missing after a cave-in at a construction site for a new metro line in Foshan city in southern China’s Guangdong province, the city’s transport bureau said on Thursday.

Another nine people were taken to hospital with non-life threatening injuries after the construction collapse on Wednesday evening, Chinese state media cited the transport bureau as saying.

A section of road and pavement lined with streetlights had crumbled and sunk into the ground, leaving a nearby bus stop perched on the edge of the hole, according to pictures and video from state media.

The site was part of construction for Foshan’s second metro line, wrote reuters.com. 

Rescue efforts and an investigation into the cause of the collapse were underway, the transport bureau said.

Workplace accidents are relatively common in China, which faces problems with poor oversight and enforcement of health and safety standards.

Numerous cities across China are installing underground metro systems at a rapid pace as part of a nationwide push to upgrade urban transport.