“The Ground is Collapsing”: A Sinkhole Warning from the Urban Core

Ki-hyung Park, Communications Committee Chairman

Korea Institute of Labor Safety and Health

Translated by Michelle Jang

2025

In the heart of a city a seemingly stable road suddenly gave way. A taxi driver on his morning shift suddenly found his front wheels trapped in the collapsing ground, while a student on the way to school had to quickly step back in alarm. The 2025 sinkhole incidents at the construction site of the Sinansan Line’s underground double-track tunnel in Gangdong-gu, Seoul and Gwangmyeong, Gyeonggi Province, was more than just a ground collapse—it starkly exposed the structural vulnerabilities of today’s urban landscape.

Such sudden collapses cannot be seen merely as issues of geology or flaws in physical infrastructure. This growing risk stems from a combination of factors: the instability of underground spaces, the normalization of climate-induced disasters, and profit-driven development by construction interests that often shirk institutional responsibility. As a result, the safety of both citizens and workers is increasingly at risk.

A sinkhole is not just a warning—it challenges the very way we have managed and developed our cities, serving as a clear symptom of overlapping crises. That is why it is more urgent than ever to move beyond the narrow view that reduces the structural risks of underground urban spaces to mere technical or physical issues.

Confronting the Roots of Growth and Development-Oriented Ideologies

Sinkholes occur when underground cavities suddenly collapse. Unlike gradual ground subsidence, sinkholes involve sudden, localized vertical collapses, making them especially dangerous. When they appear in urban areas or on roads, they pose immediate threats to pedestrians and drivers, and can lead to serious industrial accidents for delivery workers, transport drivers, and construction laborers who work on or beneath these surfaces.

So, what makes the ground beneath us so fragile? Common explanations point to changes in groundwater levels caused by urbanization; an increase in impermeable surfaces; aging underground infrastructure such as sewer systems; poor soil compaction during excavation; groundwater leakage; and soil erosion from burst water pipes. However, these are not root causes—they are symptoms. The increase in impermeable surfaces due to urban development significantly reduces groundwater levels. At the same time, leaks from old water systems and unplanned discharge from public facilities cause irregular rises in groundwater, weakening the structural foundations of nearby buildings and infrastructure.[1]

This is not a natural phenomenon but the result of poorly planned urbanization. On top of that, the climate crisis is intensifying the unpredictability and risks through more frequent and intense downpours, which rapidly raise groundwater levels. During heavy rains, overwhelmed sewer systems fail to drain water efficiently, leading to further subsurface pressure. Sinkholes often form in areas near subway construction sites and large-scale underground public facilities, where these vulnerabilities are most concentrated.

In this context, an even more critical issue lies in the development and growth-centered urban policies of Seoul and the greater metropolitan area. Today, the underground of a city can no longer be described in neutral terms as merely the space beneath roads or buildings. Urban underground spaces are densely packed with complex, interconnected networks—water and sewage systems, electric power lines, and transportation infrastructure. These underground spaces are essential to urban life, functioning as both vital infrastructure and a key site for capital accumulation.

Although officially developed under the banner of “public interest,” their design and operation are in reality dominated by private construction capital. Citing goals such as alleviating congestion, improving traffic flow, and enhancing public services, the Seoul Metropolitan Government and other local authorities are pushing forward massive underground development projects—including subways, underground roads, and commercial and logistics complexes such as the GTX (Great Train Express). Much of this development prioritizes the efficiency and profitability of urban space and is carried out through private investment schemes. These projects are typically justified through cost-benefit analyses, where profitability and expedited construction are favored over public accountability.

As development potential on the surface reaches its limits, the logic of development is now being extended underground. As noted in the Report on Legislative and Policy Measures for the Prevention of Ground Subsidence,[2] such private-led development threatens to undermine public oversight and weaken safety standards. And as already saturated underground spaces come under increasing pressure from dense infrastructure, the urban subsoil—its ground layers and groundwater systems—will become even more vulnerable, heightening the risk of sinkholes across the city.

Who Faces the Most Danger in the City?

The need for national-level measures to prevent ground subsidence came to the forefront following the large-scale sinkhole incident near the Seokchon underpass in Songpa-gu in 2014. In response, the Special Act on Underground Safety Management was enacted in 2016, mandating underground safety impact assessments both before and after the start of underground construction. A National Master Plan for Underground Safety Management was established to enhance underground safety technologies and to develop an integrated underground space map and a comprehensive underground safety management system based on digital data. The Seoul Metropolitan Government also launched a dedicated unit, the Underground Safety Division, to oversee subsurface safety. It has expanded its use of GPR (Ground Penetrating Radar) and announced plans to fully implement advanced smart safety technologies—including 3D underground mapping, HydroGeoAnalyst (HGA), and smart monitoring systems—at construction sites across the city.

However, the technological approach has inherent limitations. While technology can facilitate early detection of potential problems, it cannot eliminate the risks themselves. Moreover, no matter how much effort is made to predict such events, the accuracy of these predictions remains limited, as sinkholes are highly unpredictable incidents that can occur anywhere and at any time. A Study on Policy Improvements for the Prevention of Ground Subsidence in Urban Areas[3] also highlights that technology tends to serve more as a post-incident response tool rather than a means of proactive prevention. Furthermore, risk detection data is primarily concentrated in central commercial districts and large-scale construction sites, which means that residential neighborhoods, aging infrastructure areas, and low-income communities are likely to remain as invisible zones of risk. Equally concerning as this inequality in risk distribution is the lack of information transparency. While A Preliminary Study on the Development and Utilization of Ground Subsidence Risk Maps in Gyeonggi Province[4] stresses the importance of public access to information on underground hazards, in practice, many local governments—including Seoul—avoid disclosing ground subsidence risk maps due to fears of potential declines in real estate values.

Roads, where sinkholes most frequently occur, are not only spaces where ordinary citizens move and live, but also workplaces for delivery riders, delivery workers, and bus drivers. In this sense, a sinkhole that suddenly opens up on a road is not just a physical threat to both above-ground and underground workers and citizens—it also poses a risk that can disrupt and even destroy their daily lives. However, because workers and citizens are not considered actual stakeholders in urban planning or permitting processes, they are not even guaranteed access to safety information related to sinkholes.

Delivery workers and riders spend long hours on the road under precarious contract arrangements. For them, the road is both a workplace and a livelihood. Yet this workplace rests on unstable ground that could collapse at any moment—making sinkholes a matter not only of safety but also of labor rights. The non-disclosure of information conceals these dangers by subordinating public safety to concerns over property values and capital profits. At the same time, technological solutionism overlooks the democratic principles of urban governance and neglects the rights of workers to a safe and healthy working environment.

Moreover, civil disasters or industrial accidents caused by sinkholes fall into a legal blind spot. The current Serious Accidents Punishment Act does not explicitly include “roads” as facilities subject to serious civil disasters, making it difficult to impose effective penalties in the event of road collapse-related incidents. The aforementioned report by the National Assembly Research Service identifies this as an institutional gap and proposes several key policy alternatives: redefining the facilities covered under the law, restructuring the licensing system to prioritize prevention, and expanding civic oversight powers. However, the gap between legislation and enforcement remains significant.

In most cases, legal responsibility after an accident is limited to subcontractors or on-site personnel, while institutional heads, public officials, and commissioning bodies are relatively exempt from accountability. This situation not only infringes upon the basic rights of worker-citizens but also reveals that the legal and institutional framework is failing to uphold its duty to protect the safety and well-being of the community. The legislative gap is not merely the absence of regulation—it reflects an ethical choice about whose lives are protected and whose lives are left unprotected. Instead of reducing the causes of such accidents to individual negligence, we must pursue a system of structural accountability that links every stage—from licensing and construction to ongoing management.

A Prerequisite for Urban Safety: Restoring Public Values and Democracy

Sinkholes are not merely physical phenomena of ground collapse; they expose the fragile condition of cities and the erosion of public values and democracy in the living and working spaces of working citizens. It is a compounded disaster created by a city that conceals risk, an administration that outsources responsibility, and a political system that excludes public participation. We must no longer ignore the warnings that sinkholes send us.

The underground spaces where sinkholes occur lies at the heart of the administrative and corporate power that shapes the city. At the same time, it is one of the most vulnerable spaces for democracy. Citizen participation in urban governance has remained largely symbolic. Public hearings, briefings, environmental impact assessments, and safety evaluations, when conducted without meaningful participation and oversight, are effectively meaningless.

Urban safety can only be ensured when citizens and workers—the main agents of everyday life—participate in the design and operation of urban spaces. This involves granting citizens real decision-making authority over the layout of urban infrastructure, development priorities, and methods of implementation—not merely gathering their opinions. A new urban democracy must be established—one that prioritizes the lives of working citizens and breaks away from developmentalism, growthism, and undemocratic practices.

[1] Jin-Yong Lee, and Min-Ho Koo (2007) Impacts of Urbanization on Groundwater and Issues Concerning Groundwater in Urban Areas. Journal of the Geological Society of Korea, 43(4): 517–528

[2] Jin-Soo Kim (2025) Legislative and Policy Measures for Preventing Ground Subsidence. Current Issues Analysis, No. 354. National Assembly Research Service (NARS).

[3] Seok-min Lee and Hyeong-mi Yoon (2017) A Study on Policy Improvements for the Prevention of Ground Subsidence in Urban Areas, Seoul Urban Studies Vol. 18 No. 1, 27-42

[4] Ki-young Lee et al (2014) A Preliminary Study on the Development and Utilization of Ground Subsidence Risk Maps in Gyeonggi Province, GRI Policy Research