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.

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 ...

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 ...