On Monday, as companies all over the Bay Area rushed to send their workers home, complying with an order to shelter in place, Tesla Chief Executive Elon Musk had a defiant message for his 56,000 workers.

“I will personally be at work, but that’s just me,” he said in an email. “Totally ok if you want to stay home for any reason.” Tesla’s Fremont, Calif., factory kept humming, even as the county sheriff’s office the next day said publicly that Tesla should stop production.

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