BEIJING (AP) — Rescue efforts ended at a two-story restaurant in a northern Chinese village that collapsed during a local resident’s 80th birthday celebration, leaving 29 people dead, authorities said Sunday.

The Ministry of Emergency Management said another 28 people were injured, seven of them seriously, when the building suddenly crumbled on Saturday.

There was no immediate word on what caused the collapse or on the fate of the birthday guest and other celebrants.

Hundreds of rescue workers using sniffer dogs, cranes and high-tech sensors had searched the rubble, lifting slabs of concrete in hopes of freeing survivors.

The official China Daily newspaper said the building collapsed at 9:40 a.m. Saturday. It said the Cabinet’s Work Safety Commission would oversee the investigation into the accident’s cause.

While China has seen major improvements in industrial safety, building standards are sometimes ignored, particularly in rural areas such as Shanxi province’s Xiangfen county, about 400 miles southwest of Beijing, where the restaurant was located.

The region lies in the heart of China’s coal country, where thousands of miners have died in explosions, collapses and floods over the years.