A Japanese civic group is spearheading efforts to recover and identify the remains of victims from a 1942 flooding accident at the Chosei undersea coal mine in Ube, Yamaguchi Prefecture. The mine disaster claimed 183 lives, including 136 workers from the Korean Peninsula, when an abnormal inflow of water flooded the mine about one kilometer from its entrance on February 3, 1942. The mine entrance was subsequently sealed, leaving the victims’ bodies inside.

Since its establishment in 1991, the civic group has conducted independent underwater investigations at the site after the Japanese government declined to authorize official searches, citing uncertainty about the remains' locations. Funding for these operations has been primarily raised online. In August 2025, divers operating through an exhaust and drainage shaft successfully recovered human bones, including a skull.

Following these findings, the group requested the governments of Japan and South Korea to initiate joint DNA analysis to identify the recovered remains. This request coincided with a January 2026 summit between the two countries’ leaders, during which they agreed to collaborate on the identification process and expedite related procedures starting in May.

Teams from Japan’s Foreign Ministry and a South Korean expert organization subsequently visited Yamaguchi Prefecture to collect samples for analysis. Yoko Inoue, 76, who represents the civic group, highlighted the significance of citizen-led initiatives in advancing the DNA research and urged the Japanese government to assume a leadership role in the search and recovery operations going forward.

The group suspended its dives following the death of a Taiwanese diver during an underwater probe conducted at a memorial ceremony in Ube in February 2026. It has since announced that it will not resume its investigations until a memorial event scheduled for late January 2027.

Plans are underway to restore the drainage shaft as part of a broader project to establish a peace park at the former mine site, creating a lasting tribute to those who perished in the disaster.