An Oregon appeals court on Wednesday ruled in favor of PacifiCorp in litigation over a series of Oregon wildfires in 2020, saying a trial judge erred in letting the case against the Berkshire Hathaway-owned utility proceed as a class action.

The decision by the Oregon Court of Appeals in Salem could reduce PacifiCorp’s overall liability, which the utility has estimated could total tens of billions of dollars.

PacifiCorp has denied claims by thousands of Oregon residents and business owners who accused it of causing several wildfires by negligently failing to shut off power lines during a Labor Day weekend windstorm in 2020.

The appeals court said a trial judge overseeing the litigation erred in instructing jurors they could “assume that the evidence at the trial applies to all class members,” and that the error was prejudicial to PacifiCorp.

Lawyers for fire victims did not immediately respond to requests for comment. PacifiCorp did not immediately respond to similar requests.

(Reporting by Jonathan Stempel in New York; Editing by Chris Reese)