SAN FRANCISCO (KRON) — OpenAI employees said they are ready to make a mass exodus from the San Francisco-based artificial intelligence tech company after their CEO was unexpectedly booted.

More than 500 employees wrote a letter to OpenAI’s board of directors accusing board members of “destroying” the world’s leading AI company and terminating CEO Sam Altman without evidence that it was necessary.

Altman’s sudden departure from the company happened on Friday, just one day after he spoke at the Asia-Pacific Economic Cooperation summit in San Francisco’s Moscone center. He also delivered a keynote address on November 6 at the first-ever Open AI DevDay conference in San Francisco.

In their letter, employees reminded the board that OpenAI’s workers developed “the best models and pushed the field to new frontiers. “The products we built are used by millions of people around the world. Until now, the company we work for and cherish has never been in a stronger position,” the letter states. OpenAI created ChatGPT.

The letter continues, “The process through which you terminated Sam Altman and removed Greg Brockman from the board has jeopardized all of this work and undermined our mission and company.”

Dozens of employees tweeted “OpenAI is nothing without its people” on X Monday. Altman replied on X with heart emojis.

Employees accused the board of incompetence and failing to show evidence for why Altman was terminated. The letter demands that board members step down.

“The most stabilizing path forward – the one that would best serve our mission, company, stakeholders, employees and the public – would be for you to resign and put in place a qualified board that could lead the company forward,” the letter states.

In an interview with KRON4 at APEC on Thursday, Mayor London Breed talked about the Bay Area tech industry’s contributions to the world of AI and Altman’s work.

On Monday, the mayor’s office said it is monitoring the company’s rapidly evolving leadership changes.

The mayor’s office wrote, “This does not change the fact that San Francisco is still the place to be for AI. We are confident that, however this situation ends up, this City is still positioned to be the center of this groundbreaking industry. This is a growing and dynamic industry and we are excited to be at the heart of it.”

Following news of the board ousting Altman on Friday, OpenAI President Greg Brockman announced he was resigning. Both men have since been hired by Microsoft.

The Associated Press contributed to this report.