In a SEC filing on Wednesday, California utility PG&E revealed that a pre-drawn outage on the Caribou-Palermo 115 kilovolt transmission line in Butte County on November 8 may have been what sparked the Camp Fire, which since killed at least 56, and destroyed more than 16,000 homes and buildings, while continuing to still burn. An attorney for victims of the fire reportedly said there were several witnesses who saw the fire form from a power line.

Cal Fire said in a statement that the Cascade Fire started due to high winds causing two sagging PG&E power lines to come into contact with each other, creating “an electrical arc.”

Now, investors are beginning to assume the worst. PG&E shares, dropped 20 percent Wednesday and down another 27 percent on Thursday. In addition, the yield on PG&E senior notes blew out to 7.09% Wednesday, from 5.40% a month ago, according to Bloomberg data. The company has roughly $18 million in long-term debt outstanding against $71 billion in total assets.

Forbes reports that the utility market cap is now $9.5 billion, though it’s difficult to imagine how the equity would hold any value, unless the company is capable of convincing regulators to stick ratepayers with the cost. Analysts from Citigroup, JPMorgan and Mizuho already ventured that the regulated utility will be dealing with  liabilities on the order of $15 billion for the Camp Fire – on top of another roughly $15 billion in damages from 2017’s fires in wine country that killed more than 50. PG&E said its insurance coverage for the Camp Fire was only about $1.4 billion.