Three senior researchers at OpenAI resigned Friday night as the artificial intelligence developer suffered fallout from the firing of CEO Sam Altman and sudden resignation of President Greg Brockman, according to several people with knowledge of the situation.

Jakub Pachocki, the company’s director of research; Aleksander Madry, head of a team evaluating potential risks from AI, and Szymon Sidor, a seven-year researcher at the startup, told associates they had resigned, these people said. The departures are a sign of immense disappointment among some employees after the Altman ouster and underscore long-simmering divisions at the ChatGPT creator about AI ‘safety’ practices.