Cracks Found in Sewage Pipes Before Sinkhole Incident in Myeongil-dong

Cracks and defects in the sewage pipes near the site of a sinkhole incident in Myeongil-dong, Gangdong-gu, Seoul, were identified prior to the event. The Seoul Metropolitan Government had communicated the findings of the investigation to the Gangdong District Office, but no follow-up measures to verify actual maintenance were taken.

According to Rep. Bae Seung-chan of the Democratic Party, a member of the National Assembly's Land, Infrastructure and Transport Committee, the contractor for the first section of the Seoul Subway Line 9 extension project submitted a report to the city after inspecting the sewage pipes in the area during construction.

The report indicated that defects such as joint failures, surface damage, and longitudinal cracks were found in the 201 line adjacent to the accident site.

After receiving the report, the Seoul city government sent a cooperation request to the Gangdong District Office, the managing authority for the sewage pipes. In the letter, the city requested, "Please ensure that the sewage pipes are maintained in advance to allow for the safe execution of this project."

However, no separate maintenance actions were taken. According to information obtained by Rep. Bae's office through a public information request from the victims' families, the Gangdong District Office assessed the structural condition of the sewage pipes in the sinkhole area as 'good' or 'very good' based on the report, concluding that there was no urgent need for maintenance.

The Gangdong District Office stated, "No separate actions were taken, and there were no identified defects." Although cracks and joint failures were confirmed in the contractor's investigation, they determined that there was no need for additional maintenance based on a comprehensive evaluation of the structural condition.

While the Gangdong District Office is the direct managing authority for the sewage pipes, Rep. Bae's office pointed out that the Seoul city government also has responsibilities and authority regarding ground subsidence prevention and underground safety management.

Article 38, Section 1 of the Special Act on Underground Safety Management allows city and provincial governors to order safety measures such as repairs and reinforcements when there is a risk of ground subsidence. The Seoul Metropolitan Ordinance on Underground Safety Management also mandates that related agencies cooperate and include measures in the city's underground safety management plan.

The accident investigation committee identified 'leakage from aging sewage pipes' as an indirect cause of the incident in a report released last December. However, the report also noted that the design department of the Seoul Urban Infrastructure Headquarters requested cooperation from the Gangdong District Office based on the investigation results of the sewage facilities, stating that 'minor and long-term leakage from the sewage pipes made it difficult to confirm.'

Rep. Bae stated, "Signs of cracks and joint failures in the sewage pipes were identified even before the accident, and the contractor conveyed their concerns, but the Seoul city government did not check whether any actions were taken after informing the Gangdong District Office. Since the city is not completely free from responsibility for underground safety management, it is essential to clarify whether the preemptive responses of both the city and the district office were appropriate during the accident investigation process."