Close on the heels of the departure of its AI ethics researcher Timnit Gebru, Google has now fired Margaret Mitchell, the founder and former co-lead of the company’s ethical AI team.

Mitchell announced the news on Twitter.

Both Gebru and Mitchell had called for more diversity and inclusion among research staff. “Firing [Gebru] created a domino effect of trauma for me and the rest of the team, and I believe we are being increasingly punished for that trauma,” Mitchell tweeted on the same day.

In a public letter concerning Dr. Gebru’s departure, Mitchell earlier said: “The firing seems to have been fueled by the same underpinnings of racism and sexism that our AI systems, when in the wrong hands, tend to soak up. How Dr. Gebru was fired is not okay, what was said about it is not okay, and the environment leading up to it was — and is — not okay.”

On her dismissal, Google claimed that Mitchell violated the company’s code of conduct, as well as security policies.