My opa was also a Dutch POW and I believe he was working in that same mine on the same day. When it happened, he was deep in the mine, which was evacuated because people inside initially thought the blast was an earthquake. Being a POW was without question extremely hard, but it was the bombing of Hiroshima that resulted in PTSD lasting many years after the war. He survived, retiring in Florida, and passed away in the late 80s. Some US government scientists asked if they could study his body, believing radiation exposure affected his long term health. It seems they were correct because his bones were found to have a slightly blue tint to them.