UBE, Yamaguchi -- Two months after the start of hostilities along the Pacific front in World War II, 183 souls lost their lives in an inundation of an underwater coal mine off the coast of this west Japan city. On Oct 29, divers began research with the aim of collecting their remains.

In the February 1942 incident, 136 laborers from the Korean Peninsula and 47 Japanese workers died. The group conducting the survey hopes to return their remains to their respective homes, and is studying the prospect of a comprehensive survey based on the state inside the former mine, where the remains have been left behind.

The Chosei coal mine was located off the Tokonami shore in the Seto Inland Sea. Two cylindrical structures which jut out of the water remain in place, referred to as "piers," which served to ventilate and expel water from the former mine.

Entering from the pier structure closest to shore on Oct. 29 were 36-year-old diver Yoshitaka Isaji and others. The inside was filled with freshwater thought to be from rainfall. Around 23 meters below the water's surface, the divers were stopped from progressing further down the shaft by obstructions such as pipes and pieces of wood. "To get into the mine from the pier, we'll need to remove the pipes and other things," Isaji noted.

The research is being done by a local citizen's group dedicated to uncovering the history of the flooding disaster. Since the group's founding in 1991, it has hosted annual memorials for the accident. It had also asked the national government to collect the remains, but the labor ministry has responded, "The unclear location and depth of remains makes it difficult to investigate at this time."

Not wishing to make relatives of the deceased wait any longer, the group turned to crowdfunding to get the research underway. In late September, they discovered an entrance to the sealed-off former mine about 4 meters underground along a shoreline.

On Oct. 30, the divers were set to enter the mineshaft from the recently discovered entrance, check the conditions inside and collect any remains if found. Studies had previously been done inside the piers, but this was to be the first time for divers to venture through the underground entrance.

The group's co-representative Yoko Inoue said on Oct. 29, "Above all, I'm relieved that the research was done safely, and I'm hopeful the study on the 30th will reveal some key points."

(Japanese original by Hidenobu Fukuhara, Yamaguchi Bureau)