Check out this site Karen, if you are not aware of it, you may find it rather interesting. Valery Uvarov talks of some strange thing seen in the sky at, or near, the time of the Tunguska event.
One that caught my attention was witnesses saying that the sky split open and there was a dark wedge where stars could be seen. That sounded to me like whatever it was, had removed a wedge of the earth's atmosphere so that sunlight wasn't being scattered and consequently, no blue sky.
Tesla? Could be.
http://www.bibliotecapleyades.net/esp_autor_uvarov.htm