Shenzhen: Authorities launched an "all out" search operation after 13 workers went missing following a sudden ground collapse at a railway construction site in China's southern Guangdong province, state media reported on Thursday. The incident occurred in Shenzhen city late Wednesday, with an investigation into the accident currently underway. According to Anadolu Agency, authorities evacuated nearby residents and implemented temporary traffic restrictions in the area surrounding the site. The search operation is ongoing as rescuers strive to locate the missing workers amidst challenging conditions. The collapse has raised concerns over construction safety standards in the rapidly developing region, prompting calls for a thorough investigation to determine the cause of the incident.