The Seoul Metropolitan Government reported to the Ministry of Land, Infrastructure and Transport on the 9th that the cause of the sinkhole accident in Myeongil-dong, Gangdong-gu was due to "subway tunnel construction." At the accident site, there was a tunnel created as part of the Phase 4 construction of Line 9. A man in his 30s, who fell into the sinkhole while riding a motorcycle, was found dead in the underground tunnel.
The Myeongil-dong sinkhole accident occurred near the entrance intersection of Daemyung Elementary School on March 24th. The Seoul Metropolitan Government submitted a report related to the Myeongil-dong sinkhole accident to the Ministry of Land, Infrastructure and Transport underground safety information system the day after the incident.
In this report, the Seoul Metropolitan Government cited the opinions of two experts in the 'detailed cause of occurrence' section. Expert A noted, "It is judged that the upper part of the tunnel collapsed, causing soil to enter the tunnel interior," and stated, "Since the lower part of the collapse is connected to the tunnel and soil and water have entered the tunnel, it is estimated that the tunnel construction is the cause of the ground subsidence."
Additionally, Expert B stated, "It is presumed that the upper part of the tunnel being constructed below the road collapsed, causing the soil on the ceiling of the tunnel and the road surface to sink," and added, "It is estimated that the tunnel collapse occurred and, as a result, the road subsided."
In response, a Seoul Metropolitan Government official said, "The two experts belong to the underground safety advisory group and conducted on-site investigations on the day of the accident in Myeongil-dong." However, the official noted, "The two experts’ opinions are not conclusive, and the specific cause of the accident will be revealed through further investigation."