[News Terms] The ‘Joseitan Coal Mine’ Flooding Accident That Claimed 136 Joseon People

Forced Deployment of Koreans in Undersea Mine Avoided by Japanese
Flooded Due to Leakage During Illegal Coal Mining in 1942
Truth Revealed by Japanese Civic Group Amid Indifference of Korean and Japanese Governments

Excavation work is underway to find the remains of the victims of the Joseitan Coal Mine flooding accident in Ube City, Japan, which occurred in 1942 during the Japanese colonial period. Since the 24th, the Japanese civic group 'Meeting to Engrave the Joseitan Coal Mine Flooding Accident into History (Saegineun Moim)' has mobilized equipment and officially started construction, and on the 25th, they discovered a place presumed to be the entrance to the coal mine.

Two ventilation shafts on the Tokonami coast in Ube City, Japan, and the appearance of the coal mine in 1933
[Photo by the Association for Recording the History of the Josei Coal Mine Flooding Accident]

Joseitan Coal Mine (長生炭鑛) is located on the Tokonami coast at the southern end of Ube City, Yamaguchi Prefecture, Japan. The two large concrete structures rising above the sea here are the ventilation shafts of the Josei Undersea Coal Mine. During the Japanese colonial period, they were the lifeline for Korean workers working in the undersea mine. They are also the only remaining traces that a coal mine existed here.

Opened in 1932, the Josei Coal Mine had a particularly large number of Korean workers and was called the ‘Korean Coal Mine.’ It was notorious for its harsh working conditions. Working in the undersea tunnels, the depth was so shallow that the engine sounds of ships passing overhead could be heard. There are testimonies that workers feared seawater would flood the tunnels. The mine shafts extended like a spider web more than 10 km under the sea. Due to the risk of accidents, Japanese workers rarely worked there, and Korean conscripted laborers were forcibly deployed to these dangerous areas.

Cross-section of Josei Coal Mine. The red area at the left end of the tunnel is the point where leakage occurred.
[Photo by Josei Coal Mine Flooding Accident Memorial Group]

On the morning of February 3, 1942, about 82 years ago, at around 9:30 a.m., a flooding accident occurred in an undersea tunnel about 1 km from the coast. At that time, the Japanese Undersea Tunnel Mining Law prohibited mining shallow layers, but seawater began to seep into the tunnel while digging these shallow layers. Eventually, unable to withstand the weight of the seawater, the tunnel collapsed, and 183 workers (136 Koreans and 47 Japanese) working inside were drowned and died.

It was a clear man-made disaster. At the tunnel entrance by the sea, bereaved families and conscripted workers gathered and wept bitterly. According to witnesses, the air in the tunnel rose like a pillar of water, towering like a mountain along the coast. It was the largest coal mine flooding accident during wartime.

The Japanese government and the mining company were more focused on covering up the accident than investigating the cause. They were worried that public morale would drop amid the ongoing Pacific War. Because the tunnel entrance was sealed off, the exact location became unknown. Newspapers only reported the occurrence of the accident and the number of victims, with no further coverage. The list of victims was never disclosed.

Water is gushing out as the entrance of the Josei Coal Mine, presumed to be the mine entrance, is excavated for the first time in 82 years.
[Photo by the Group Commemorating the Josei Coal Mine Flooding Accident in History]

The first person to bring the tragedy of the coal mine to public attention was the late Takenobu Yamaguchi, a history teacher at Ube Girls' High School in Japan. In December 1976, 34 years after the accident, he published a paper titled ‘Flooding Accident in the Coal Mine - Notes on the 1942 Joseitan Coal Mine Disaster’ in the journal ‘Ube Local History Research’ published by the Ube Local History Research Association.

In 1991, the ‘Saegineun Moim’ was formed with Yamaguchi as its representative, and despite indifference from the Korean and Japanese governments, the group has continued activities such as memorial services and erecting monuments. They have located people involved at the time and bereaved families to collect testimonies and reveal the full extent of the concealed flooding accident. Additionally, from July 15 to October 13, they conducted a crowdfunding campaign titled ‘Open the Mine Entrance!’ with a target amount of 8 million yen (approximately 72 million won) to raise funds for the excavation investigation of the Joseitan Coal Mine.