A sole plate fell from a height of 10 meters at 5:20 p.m. when workers were pouring a concrete slab to build a road in Yongin, 49 kilometers south of Seoul, burying 16 under the rumble, officials said.

All of them were rescued from the site within an hour, but the incident left one dead and eight others seriously injured. Seven others suffered minor injuries, they said.

"At the time of arrival here, seven had already escaped (from the rubble), while nine others remained trapped underneath," Seo Seok-kwon, the chief of Yongin Fire Station, said in a briefing.

"The dead victim's lower body was buried under the concrete mix."

Police said they will continue to search the site and summon officials from Lotte Engineering & Construction, a local builder in charge of the site, to figure out what may have caused the incident.

The construction of the road began in late 2012 and was supposed to be completed by the end of this year, according to officials. (Yonhap)