One worker died and two others were injured with authorities having rescued all seven workers trapped at an underground construction site in Seoul on Thursday, officials said. The accident was reported at 1:22 p.m. after a steel bar collapsed at the Sinansan Line construction site for Yeouido Station in southwestern Seoul, leaving the seven workers trapped underground, according to police and rescue officials. A man in his 50s was found in a state of cardiac arrest and taken to a nearby hospital where he was pronounced dead. Another worker also in his 50s was hospitalized for a minor ankle injury. A foreign worker in his 30s came out of the site on his own and received treatment for minor scrapes on his wrist. The remaining workers evacuated to a vertical shaft before being rescued by firefighters. The accident is presumed to have occurred some 70 meters underground when a steel bar collapsed as concrete was being poured. Police plan to investigate whether safety measures were properly taken at the site.