Three miners died as a result of a strong tremor in the Murcki-Staszic coal mine in Katowice, south Poland, on Monday. Six other miners are already in hospital, the Polish Mining Group (PGG), the mine owner, said in a statement.
The tunnel, 40 metres underground and started in 1799, is the latest attraction in a process that has seen Zabrze repurpose its former coal mining infrastructure for tourism. The whole tour takes 2.5 hours, most of which is on foot and the journey finishes with a 30-minute boat ride.
Rescuers are searching for three miners after the Zofiowka mine in Jastrzebie-Zdroj, southern Poland, caved in on Saturday following a series of underground tremors.