The memorial event was held near the former site of the Chosei coal mine and was attended by about 450 people.

Imagine being in a giant underwater mining and research station the size of a small city and never seeing anyone else there. And remember, the movie starts the very moment all hell breaks loose.

The area is famed for its eco-tourism. The water level rose to 10-feet during the flood, completely submerging the path underwater for two days. Produced by David Ibekwe. More from UK A triangle ...

said old mines often contain groundwater which can flood in heavy rain. He said: "A lot of them go very, very deep down, much below the local water level and that's why they had all the big wheels ...