Please tell me what is the reason for the "bit storm"? What happened? What was the result?

Explorers came to Lake Pinel. They set up drilling rigs directly in the lake to survey the strata at the bottom of the lake. They chose to drill at the edge of the underground salt mine and one side of Lake Pinel. However, the drilling work was not smooth. When drilling about 400 meters underground, the drill bit got stuck. At this time, the worker's first reaction is to loosen the drill bit. Suddenly there was a violent explosion, and the workers rowed the boat to escape, but they saved their lives.

Within minutes, the workers watched the rig disappear from sight. It is worth noting that the height of the drilling platform is about six stories high, so it sank quickly and Pinel Lake formed a huge whirlpool. A deep pit immediately appeared at the bottom of the lake,13 billion liters of water disappeared, and the town disappeared. What is that scene? I dare not think about it. What's more frightening is that it's not over yet. Due to the huge suction of the vortex, the Delgan Canal next to it also changed direction, and the seawater began to flow back to Lake Pinel.