Based on the testimonies of the station workers, we substantiate the hypothesis that the main cause of the accident was the beginning of planned harmless electrical tests. The station was in ruins 20 seconds after the start of the test. Ball lightning appeared as a result of switching strong currents. Ball lightning created a defect in which relaxation oscillations arose. These oscillations gradually increased the defect, which ultimately led to an explosion. Evidence of the occurrence and destructive effects of ball lightning are provided. Based on numerous literary sources, we have shown that ball lightning leaved exactly the same consequences that the station workers talk about. In addition, we present an APPENDIX with the optical theory of ball lightning, where we show that ball lightning has the same properties as those described in literary sources. This additionally confirms the properties of ball lightning, which are given in support of the hypothesis.In accordance with the optical theory of ball lightning there is no electricity, plasma, electrodynamic processes and chemical reactions. There is nothing but white light and ordinary atmospheric air, where ball lightning is located. Light rotates in a thin spherical layer of compressed air in all possible directions. Compressed air is a light guide that prevents light from being emitted into the surrounding area. In turn, the rotating light compresses the air in which the light rotates, due to the known physical effect of electrostriction pressure. Thus, ball lightning is a symbiosis of rotating light and compressed air. Unlike a soap bubble, in which its spherical shape is provided by the excess air pressure in the volume limited by the soap film, the spherical shape of the light bubble is provided by the centrifugal forces of the rotating light. Believing a priori, that bubbles of light are an objective reality, we have shown that in accordance with well-known laws of physics behavior of bubbles of light in the conventional air atmosphere is completely identical to mysterious and paradoxical behavior of natural ball lightning. Too many puzzles related to ball lightning can be explained by the assumption that ball lightning is a bubble of light.The main property of a light bubble and therefore natural ball lightning is its movement in the direction of increasing the density of the gas in which it moves. This property allows us to explain almost all the anomalies in the behavior of natural ball lightning.With regard to the movement of ball lightning in the steam line, it follows that unlike movement of all known objects along the gas velocity, the bubbles of light moves in a steam line against gas motion. Indeed, the gas moves from the space with high pressure to the space with lower pressure. The high pressure corresponds to the greater air density. Then bubbles of light move towards the great air density that is opposite to the motion of the gas. Once in the steam line, ball lightning moved against the movement of the steam, that is, to the mine with fuel elements.In video yellow circles present ordinary objects that move along the gas flow. White circle presents the bubble of light that moves opposite the gas flow.References on the mentioned above three dozen articles are given in the book end. The articles are free accessible at Research Gate at https: //www.researchgate.net/profile/Vladimir_Torchigin