SONOMA (AP) – Pacific Gas & Electric Co. shares plummeted 10.5 percent, after state regulators directed the company to preserve any evidence of failed poles, conductors or other equipment that might be connected to Northern California wildfires that killed 32 people.

The steep one-day fall Friday means the value of the giant utility, or market capitalization, dropped about $3.5 billion, from $33.1 billion to $29.6 billion. The fires have destroyed 5,700 homes and businesses.

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While the causes of these wildfires have not been determined, early 911 calls show people in Santa Rosa reporting blown transformers and downed power lines just as the fires were beginning.

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Fire officials are investigating whether downed power lines and utility equipment failures may have caused some of the wildfires devastating Northern California’s wine country.

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