Without offending anyone and simply citing it for historical reference, it could, with that logic, also reference the Holocaust and Auschwitz and what was done there. They literally cremated a lot of Jews so that, in the event of a seize, they would have no evidence of a crime. Also, so many people perished there that ground for burial came at a premium. There was simply no room. Crematoriums, or "ash factories", produced so much ash from so many burning bodies that ash literally fell from the sky like snowflakes. Also, you misread the description. The word is " blot", not bolt. Blot has an entirely different meaning. It in fact means, in this case, to "completely cover or obscure its view".