Huge swaths of central and Northern California were likely to be without power on Wednesday as their state’s largest utility intended to cut power. The utility said that roughly 800,000 customers would be affected from Silicon Valley into the foothills of the Sierra’s door step, in stages.

Winds are expected on Thursday and Wednesday. Peak season is here in California, with a mixture of high winds and low humidity creating conditions for fires that were potentially devastating. Pacific Gas & Electric says it is proactively shutting power off to prevent its equipment out of igniting a blaze.

The company was found in charge of dozens of wildfires in the past few decades, including their state’s most deadly .

Through the summer power was deterred by the utility into areas in Northern California, but this is definitely the very extensive shutoff the company has carried out, affecting large parts of the San Francisco Bay region.