A sinkhole in Seoul that led to a fatal accident is now being linked to ongoing subway extension construction. It has been revealed that just a month before the incident, a construction worker involved in the project had filed a complaint with the city, warning of a potential collapse.

The complaint specifically pointed to the exact location where the sinkhole formed. However, Seoul city officials dismissed concerns, responding with a generic assurance that there were "no issues." This has sparked criticism over whether the city’s response was overly complacent.

According to a CBS No Cut News investigation on March 25, a construction industry insider who participated in the 'Phase 4 extension project of Subway Line 9, Section 1' had filed a complaint with the Seoul city government on February 24, expressing concerns about a possible collapse at the construction site.

The area in question was the "Section 1 endpoint tunnel zone," directly beneath the site of the fatal sinkhole incident. The insider warned that the ground in Section 1 was weak and at risk of collapse due to unstable soil conditions.

The whistleblower stated, "I understand that there is no bedrock layer in the tunnel section of the Section 1 endpoint. Given that the area is densely populated with residential buildings and heavy traffic, I believe the pressure on the ground is significant." Reports confirm that the soil in the sinkhole area consisted of weathered earth rather than solid rock.

Despite this early warning, Seoul city officials responded only with a broad reassurance, stating, "While construction methods may vary, the project has been designed to ensure stability."

If an investigation into the incident finds that the previously reported concerns about weak soil and high pressure were valid, criticism of Seoul’s handling of the complaint is expected to intensify.

The fatal accident occurred on March 24 at 6:29 PM near Daemyeong Elementary School in Gangdong District when a sinkhole opened up at an intersection, resulting in the death of a man in his 30s. Seoul Metropolitan Government’s Urban Infrastructure Division official Lee Jae Hyuk acknowledged, "The accident site almost exactly matches the tunnel excavation area," adding that "the tunnel construction was in progress, with only the upper section being excavated at the time."

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