Only months after workers at Tesla’s Fremont, Calif. auto plant complained about grueling work conditions, the electric car manufacturer is once again at the center of a labor controversy. Elon Musk’s company was hit Monday with a class-action lawsuit calling the same Fremont plant a “hotbed for racist behavior.”

This is the third lawsuit filed against Tesla this year for racist treatment of black workers and subsequent negligence by the company, per Business Insider. The newest suit was filed by former Tesla employee Marcus Vaughn, who seeks to sue on behalf of himself and more than 100 other black Tesla employees who have faced discrimination in the workplace. According to Bloomberg, goals of the suit include punitive damages as well as the implementation of Tesla company policies to prevent workplace racism in the future.

"Although Tesla stands out as a groundbreaking company at the forefront of the electric car revolution, its standard operating procedure at the Tesla factory is pre-Civil Rights era race discrimination," Vaughn’s complaint said. The complaint was filed at Alameda County Superior Court in Oakland, Calif.

Vaughn was fired from the Fremont plant in late October with “not having a positive attitude” listed as the cause of termination. According to Vaugh, this came after he filed a complaint to human resources and Musk about Tesla employees repeatedly using racial epithets around him and his black co-workers in the plant. A crucial detail is that workers at the Fremont plant have not unionized, though Bloomberg says the United Auto Workers have an ongoing campaign to make that happen.

Adding insult to injury is an email Elon Musk sent to factory employees on May 31, per Bloomberg.

“Part of not being a huge jerk is considering how someone might feel who is part of [a] historically less represented group,” Musk wrote. “Sometimes these things happen unintentionally, in which case you should apologize. In fairness, if someone is a jerk to you, but sincerely apologizes, it is important to be thick-skinned and accept that apology.”

The email drew criticism from The Root as well as California Civil Rights Law Group attorney Larry Organ. Organ’s law firm sued Tesla on behalf of other black employees this year. Central to the criticism is the idea that victims of pervasive racial harassment cannot simply “be thick-skinned” and shake it off.

The claims of discrimination made by Vaughn’s lawsuit fit into a trend of marginalized tech workers facing harassment on the basis of their identities. A study by the Kapor Center earlier this year found that around 40 percent of surveyed former tech workers said “unfairness or mistreatment” influenced their decision to leave their job. According to the study, marginalized tech workers were harassed, stereotyped and passed over for promotion on the basis of race, gender and sexuality.

This is also not the first time Elon Musk has come under fire from progressives this year. He controversially joined Donald Trump’s advisory board early in the Trump administration before hastily leaving after Trump withdrew the U.S. from the Paris climate accord.