An autopsy has concluded that a planned power shutdown did not cause the death of a Northern California man dependent on oxygen who died about 12 minutes after PG&E shut down power in El Dorado County, California, on Wednesday.

The El Dorado County Sheriff's office said Friday that 67-year-old Robert Mardis died from severe coronary disease. The office said the power outage was not a cause of his death and that the investigation has closed.

Pacific Gas & Electric had shut off power to roughly 2 million people due to wildfire risk. It says electricity will be restored to 98% by Saturday.

El Dorado County Fire Chief Lloyd Ogan said fire crews arrived at a residence in Pollock Pines after 3:30 a.m. to find the man, in his 60s, unresponsive.

"It's devastating beyond words," said Gov. Gavin Newsom before the autopsy's findings were released. "Losing a family member is horrific and to the extent this was the reason why I hope that is investigated and I hope those responsible are held to account."

The death was first reported by the Mountain Democrat in Placerville.

A PG&E spokesman said the utility has not been able to confirm the accuracy of the report. The utility cut power to nearly 2 million people Wednesday to prevent its equipment from sparking wildfires during dry, windy weather.

Marie Aldea had previously told KCRA that her 67-year-old father Robert Mardis Sr. may have not been able to reach his battery-operated backup machine in time when the power went out.