524 Koreans died due to an American naval mine.
https://en.wikipedia.org/wiki/Ukishima_Maru>On 22 August 1945, Ukishima Maru was carrying 3,725 Korean labourers and their families from a military facility in the Aomori prefecture, headed towards the Korean port of Busan. On the 24th, the ship entered the port of Maizuru, where the ship struck an American naval mine, exploded and sank, killing 524 Koreans on board, according to Japanese government figures.https://www.youtube.com/watch?v=yu8StJG9ZTA 