At 2100m (6890ft) underground, two Russian explorers begin their journey into the lowest levels of Veryovkina [cave] where, approximately a week later, water suddenly plummeted into these chambers, quickly filling everything up and making this a giant lake bubbling and jostling off the walls. This picture shows the shaft in pretty much normal conditions. When the flood pulse came though, all this space was wall to wall white water. It was terrifying and extremely loud. I didn’t have time or the ability to make any photographs.