Rescuers search through the rubble of a collapsed restaurant in the village of Chenzhuang, Xiangfen county, Shanxi province, on Aug 29, 2020. (Photo: China Nes Service)

Frequent expansion by unqualified contractors was to blame for a deadly collapse that left 29 dead in a rural restaurant in North China's Shanxi province, according to the Ministry of Emergency Management.

The accident occurred on Aug 29 when family members and fellow villagers attended a birthday banquet for an 80-year-old man surnamed Li in the village of Chenzhuang, Xiangfen county.

It also injured 28 and caused direct economic loss of about 11.6 million yuan ($1.8 million), according to a media release from the ministry on Monday.

The restaurant was constructed without getting approvals from local authorities. Its owners also ignored the punishment from local land resources authorities and a judicial decision from a local court, it said, without elaborating.

According to Tianyancha, a business inquiry platform affiliated with the National Small and Medium Enterprises Development Fund, the company was registered in 2003.

The restaurant's owner illegally expanded the building eight times, changing the single-story building into a two-story structure with some makeshift rooms over its rooftop. With no renovation designs from people with the necessary expertise, unqualified contractors conducted the expansions completely based on their own ideas, the ministry said.

The expansions resulted in a weight that went beyond the building's carrying capacity, leaving a pillar overwhelmed for an extended period of time, it said.

The release also denounced local authorities' dereliction of duty. Despite local authorities rolling out a series of campaigns targeting illegal occupation of land, they failed to address the restaurant's illegal, long-term operation, it said.