Seosomun Overpass: Train ran for 12 hours despite warning signs before collapse

A demolition site for the Seosomun Overpass in Seoul became the scene of a fatal collapse that killed three individuals, including the site supervisor and an external expert. The incident occurred despite apparent safety concerns being noted hours before the structure gave way.

“

We installed a synthetic resin (PE) protective wall, excluding the railway crossing the accident section. We will reveal the details during the investigation.

Reports indicate that safety officials failed to halt train operations on the tracks near the demolition site for approximately 12 hours, even after signs of structural instability were observed. Early on the day of the collapse, a girder supporting the concrete upper slab was found to have sagged by 29 millimeters during slab cutting operations. This was reported to the Seoul Metropolitan Facilities Management Corporation, the project's client, by 7:30 a.m., with a face-to-face report following at 9:30 a.m.

“

We speculated that it would have been difficult to grasp that the girder would collapse on site.

Despite a meeting to devise countermeasures at 10:50 a.m., a safety assessment involving city officials and external experts did not begin until 1:40 p.m. Within an hour, the girder collapsed, leading to the deaths of three people on an aerial scaffold: the site supervisor, the site manager, and an external expert.

“

Since the aerial scaffold was installed very close to the structure, the girder could not be seen from the ground, so we had no choice but to go up to the aerial scaffold to grasp the exact condition.

The Seoul Metropolitan Facilities Management Corporation stated they did not anticipate the girder's collapse, as its safety was deemed sufficient during the demolition design phase. However, questions remain about whether structural integrity checks were conducted after the design was finalized in September 2024 and before the demolition work began in March 2025. The corporation also explained that train operations could only be halted for three hours daily between 1:30 a.m. and 4:30 a.m. on the affected section, as they had requested 24-hour work but were limited by agreements with the Korea National Railway and Korail. The investigation into the collapse's cause is anticipated to be challenging due to the fatalities of key safety personnel.

“

We requested 24-hour work from the National Railway and others, but securing three hours of work time per day was the best we could do according to the agreement with the railway authorities and Korail.