An Atlantis World (#2)
Wavering. The way the adults played it, stonemasons held their breath diving down, letting their metallic tools’ weights drag them to the right depth. They worked in shifts, dragging the tools back up with fishing lines to let the next one descend with them. Underwater, they would carefully remove the stones that held their city up, and bring them to the surface one by one. Others would wash the stones clean of algae, coat them with mortar, and place them on top of the city.
Was it a misstep that collapsed them, just one wrong hammerstrike? We will never know.