Why are the people building the most powerful AI so worried about what it could do?

The viral resignation this week of an AI researcher at Anthropic has infused fresh energy into accusations the industry is racing toward building AI that humans can't control.

British researcher Jacob Coxon wrote in a series of X posts on Tuesday that both Anthropic and OpenAI, where he worked previously, are "gambling with our lives." The two companies currently make the most capable AI systems.

Coxon told NPR's All Things Considered that his concerns arose from seeing firsthand how fast AI systems are improving.

"They're getting a lot faster very quickly, combined with the fact that we don't yet know how to safely control them, and we don't yet know whether that problem will be solved in time if we keep racing," he said.

Neither company, Coxon wrote on X, is acting responsibly. "The people building AI earnestly believe that it could kill us all by the end of the decade," he wrote.