Alphabet CEO Sundar Pichai apologized for the firing of leading AI ethics researcher Timnit Gebru in a companywide memo, following days of mounting anger at Gebru's forced departure from thousands of Google employees and leaders in the AI ethics community.

Pichai pledged to investigate the circumstances of Gebru's departure and accepted responsibility for the fact that a well-respected Black woman left the company "unhappily." Google plans to begin a review of Gebru's firing and consider whether changes should be made to prevent the incidents surrounding her departure from happening again, according to his note. "The events of the last week are a painful but important reminder of the progress we still need to make," he wrote.

"Don't paint me as an 'angry Black woman' for whom you need 'de-escalation strategies' for," Gebru wrote on Twitter in response to the apology. Pichai's memo "does not say 'I'm sorry for what we did to her and it was wrong.' What it DOES say is 'it seeded doubts and led some in our community to question their place at Google.' So I see this as 'I'm sorry for how it played out but I'm not sorry for what we did to her yet," she added.

Gebru announced last week that she had been fired from Google because she refused to accept the company's demands that she remove her name from a research paper and because of an email she wrote decrying Google's diversity efforts, setting off a firestorm of protest. More than 1,500 Google workers signed a petition in support of her work, and members of her own former AI ethics team wrote a public letter challenging Google's claims that Gebru had resigned.

Update: This article was updated at 12:35 p.m. PT with Gebru's response.