Why had Atlantis sunk down in the water

So the Atlantis inhabitants were so rich but not meaning in money species, but they had already explored all sources of stones, from the brilliance through the energetic potency, they used them as heavy adorns as a way to get an extra energy from them, they were also amulets.
 Hanging the most precious and biggest stones on the wall, the Atlantis inhabitants were elevating their findings all around, nonetheless the island was beginning to sank.
Have the Atlantis people tried to be elevated but they were just like a ship with a hole going down, and none of them had the idea of tapping the hole. They had been also admiring the water effects, a lot of rays in different colors while the water was giving the last bath on them.