Let us recall that the tragedy occurred 15 years ago, on 21 November 2006, in the coal seam 506. The wall was earmarked for liquidation, and the miners there were extracting mining equipment worth 70 million PLN. Work continued in a very high-risk area. At around 4.30 pm, a methane explosion and a coal dust explosion occurred at a depth of 1,030 metres underground. Twenty-three miners died. It was the biggest catastrophe in the Polish mining industry for almost 30 years.