Lawmakers prod Korean, Japanese governments for action on Chosei Coal Mine excavation, repatriation projects
Photos of victims of the 1942 flooding at the Chosei Coal Mine Memorial in Japan, Feb. 6 / Courtesy of Jack Greenberg
UBE, Japan — An inflatable raft returned to the beach at Tokonami in Ube City’s Nishikiwa Village at approximately 3:20 p.m. on Feb. 6. Yoshitaka Isaji climbed out with a blue plastic container in his hands, a sign to the waiting crowd that remains had been brought up. Isaji and two fellow divers had descended into the murky, cold waters to continue their search for remains belonging to 183 victims of the Chosei Coal Mine, a human-caused flooding accident that happened 84 years earlier.
The divers recovered a second skull with teeth attached following their landmark discovery of a first skull in August 2025. Additional remains were confirmed to be present in the same area. A group of bereaved family members had traveled from Korea to participate in an annual memorial and witness the dive, an opportunity they had missed the first time. Among them was Choe Geum-seok, the only child of a Korean victim among those gathered. The identity of the skull remained unknown, yet when she was brought face to face with it, the mere possibility that it might belong to her father, Choe Tae-yong, who was 35 at the time of his death, was enough, and she could not hold back her tears.
Yoshitaka Isaji carries remains excavated from a flooded mine in Japan, Feb. 6. Courtesy of Jack Greenberg
Japanese government's passivity challenged by civil society persistence
Between 1939 and 1941, 1,258 Koreans were actually mobilized to the Chosei Coal Mine of a planned total of 1,630. This represented the largest mobilization figure among all mines in the Ube coalfield. The mobilized workers hailed primarily from five localities in North and South Gyeongsang provinces (Gunwi, Yeongcheon, Yeongil, Sacheon and Goseong).
On the morning of Feb. 3, 1942, seawater engulfed the main underwater mine tunnel, trapping 136 Koreans and 47 Japanese who had been working inside. Decades later, Korea’s Truth Commission on Forced Mobilization under Japanese Colonial Rule established in its 2007 investigation that the flooding was caused by an order for miners to dig in a prohibited area vulnerable to cave-ins. Escape was then made impossible because company officials sealed the mine entrance, on the pretense of preventing seawater from surging inland to a fenced-off and guarded settlement where the miners lived.
Abandoned miner barracks, Feb. 7 / Courtesy of Jack Greenberg
For decades, the Japanese government showed a passive attitude to the issue, maintaining that even if remains were located, it could not allocate the necessary budget or secure divers as long as safety concerns remained. Progress was only achieved by a Japanese civil society organization. The Association to Engrave the Josei Coal Mine Accident in History (known in Korean as "Saeginunhoe") was established in 1991 with origins in the movement against mandatory fingerprinting of permanent Korean residents in Japan.
Through crowdfunding campaigns, it located and opened the mine entrance, which had been submerged and whose location was unknown. Subsequent rounds raised money for removal of heavy debris and supplied the expensive equipment volunteer divers needed for navigation to the partially collapsed mine passages in low visibility.
Ventilation shafts of the Chosei Coal Mine, Feb. 6 / Courtesy of Jack Greenberg
Once the association had recovered the first remains and handed them over to the Japanese police, the matter reached the Japanese government’s agenda, albeit with a narrow scope. Japanese Prime Minister Sanae Takaichi raised DNA testing and identification with President Lee Jae Myung during their summit meeting in Nara on Jan. 13. The two governments agreed to cooperate and officials from Japan’s Ministry of Health, Labour and Welfare inspected the site for the first time on Jan. 30. Working-level consultations on how to proceed remain in progress.
Members of the Korean Bereaved Family Association hold a banner commemorating the mine exploration on the beach, Feb. 6. Courtesy of Jack Greenberg
Death of diver throws future into question
Following the Feb. 6 diving survey, hopes were high that further remains could be retrieved, but the death of a member of Japan Karst & Underwater Exploration Project (JKUEP) the following day brought the effort to a halt.
Wei Hsu, 57, also known as Victor Hsuwei, was a Taiwanese rebreather trainer and instructor who volunteered to participate in this particular expedition with five other experienced divers from Indonesia (Audita Harsono), Finland (Mikko Passi) and Thailand (Naruchit Kiatmaneesri Parasu Komaradat and Sorniwit Sinlaparat).
Within the first 10 minutes of his dive, Hsuwei was exposed to high partial pressure of oxygen in his breathing gas. According to Isaji, the oxygen toxicity induced convulsions that likely caused him to drop his breathing apparatus and subsequently drown. He was brought to the surface by a team member and transferred to a hospital, where he was pronounced dead. The cause of death was later confirmed as hyperoxia.
While 3D imaging of the entire route from the second pier of the mine to where further remains was completed, the association’s activities remain in a holding pattern. After Hsuwei’s death, members have mobilized to support his family and raise condolence funds. In a statement released Feb. 13, Representative Director Yoko Inoue conveyed that Hsuwei’s family wished for the incident to be treated as an isolated one and not to impede future efforts to recover and repatriate remains, as Hsuwei himself would have opposed any reduction or halt to the work on his account.
Isaji, via a Japanese blogging platform, said he was told the same. Going forward, he plans to provide anyone participating in his projects specialized training tailored to the difficulty and stress level of the environment in question. On whether and when dives at Josei Coal Mine will resume, he intends to follow the consensus of the association and the descendants of the miners who died there.
A diver support team returns to shore, Feb. 6. Courtesy of Jack Greenberg
Lawmaker urges next steps from Korean government
Rep. Kim Jun-hyeok of the ruling Democratic Party of Korea traveled to Ube to observe the dives and take part in the annual memorial service, joining members of Korean academic, activist and religious communities. The visit marked his second year attending the event. After participating last year, he sponsored a related resolution calling for the Japanese government and international community to step up action.
Following this year’s trip, he went further, proposing a special law aimed at creating a formal institutional framework for dedicated financial support at the state level and comprehensive cooperation between relevant agencies as well as civil society. Kim’s bill was referred to committee on March 11 for substantive examination. A separate bill, introduced in November 2025 by Rep. Kang Dae-sik from the main opposition People Power Party, advanced to committee in February. Its scope centers on truth clarification and consolation payments for bereaved families, rather than issues involving remains or DNA analysis.
A skull excavated from the Chosei Coal Mine, Feb. 6 / Courtesy of Jack Greenberg
Because the Chosei Coal Mine is entangled with historically sensitive disputes between Korea and Japan over colonial-era forced and conscripted labor, the question is not only legislative feasibility but strategic prudence. Advancing legislation that presupposes cooperation with the Japanese government beyond the scope already agreed to may create friction and jeopardize first steps towards trust-based, joint action. Legislative counsel recognized the humanitarian objective to be clear, but has encouraged that the necessity and timing be evaluated against the state’s inclination to employ memory diplomacy.
Future debate can also be expected about whether Korea's Ministry of the Interior and Safety, rather than the Ministry of Foreign Affairs, should oversee the work under the existing legal framework.
Names of victims are on chopsticks at an altar in front of the mine entrance, Feb. 7. Courtesy of Jack Greenberg
Jack Greenberg works as a consultant, researcher and freelance writer. His current focus is on heritage and conservation issues, historical memory debates, truth-seeking and reconciliation, and civilian massacres of the 1950-53 Korean War. He was the recipient of the Global Korea Scholarship and earned a master’s in international studies at Korea University. He is also an alum of McGill University in Canada.