Gwangju: A worker missing after the collapse of a library construction site in Gwangju was found dead Saturday, local fire authorities said, as they continued efforts to locate the last remaining missing worker on the third day of the search operation.

According to Yonhap News Agency, the body of the 68-year-old worker, identified by his surname Ko, was discovered at around 1:03 a.m., officials said. The discovery raised the death toll from Thursday's accident to three. Of the four workers who were buried, three have been confirmed dead, while one remains unaccounted for.

Officials suspect the collapse began as workers poured concrete onto the two-story structure's rooftop, with the ground floors falling to the underground level. The library under construction was being built by the Gwangju metropolitan government on the site of a former waste incineration plant in the city some 300 kilometers south of Seoul.

The search is now focused on finding the missing 58-year-old worker, identified by his surname Kim. Authorities plan to use excavators and other heavy machinery to remove concrete in the area where Kim is presumed to be trapped.

Land Minister Kim Yun-duk said Friday that the government plans to introduce a special law to strengthen construction workplace safety and enforce tougher penalties for fatal accidents in response to a growing number of such incidents at construction sites. Since taking office in June, President Lee Jae Myung has reiterated the need for stronger measures to prevent industrial accidents following a series of accidents at workplaces managed by major construction companies.