SAN FRANCISCO (CBS SF) — PG&E is expecting a $1.15 billion financial hit from claims related to the monstrous Dixie Fire according to the utility’s latest filing with the SEC.

PG&E revealed that it received a subpoena last month from the U.S. Attorney’s office in connection with the Dixie Fire. That wildfire consumed nearly 1 million acres.

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Investigators say a burning tree leaning against a PG&E line may have sparked the fire.

PG&E executives say the $1.15 billion estimate is on the lower end of potential costs from the Dixie Fire as claims continue to pile up.

PG&E issued the following statement to KPIX regarding the issue:

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“We believe our actions around the time of the Dixie Fire’s ignition show that we are a reasonable operator of our electric system. We remain focused on reducing wildfire risk across our service area.”

Last month, five Northern California counties are suing Pacific Gas & Electric Co. over the massive Dixie Fire.

According to a statement obtained by Chico CBS affiliate KHSL-TV, Butte, Lassen, Plumas, Shasta and Tehama counties filed the suit in San Francisco Superior Court on Wednesday. The lawsuit alleges the utility’s equipment caused the fire, which burned 963,000 acres in the five counties and was the largest non-complex fire in state history.

“Tehama County brings this action to recover public and natural resources lost, because PG&E failed to manage and maintain its high voltage infrastructure,” said Dennis Garton, chair of the Tehama County Board of Supervisors.

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The lawsuit seeks damages for injuries to public resources, natural resources, lost revenues increased expenses, lost assets, infrastructure damages and other damages.