Massacre
In July, dozens of Koreans who tried to escape the construction site were gunned down or otherwise killed by the plant foremen. The workers' bodies were then dipped in cement, and cast into the Shinano River.
The massacre was exposed when the corpses of the Koreans gradually drifted from the upper course of the river over several days after the start of the construction. This caused an uproar in the parts of the Niigata Prefecture along the river. Tokyo’s Yomiuri Shimbun picked up the story on 29 July. Afterwards, Japanese-Koreans formed the Board of Inquiry into the Conditions of Resident Korean Laborers, and investigated work conditions for Zainichi Koreans.
The people who were behind the Board of Inquiry were central in the formation of the Tokyo League of Korean Labor in November 1922, and in December the Osaka League of Korean Labor was established.[1]