"Concrete Problems in AI Safety" was published, led by Dario Amodei and colleagues at Google Brain with co-authors from OpenAI, Berkeley, and Stanford. The paper framed AI safety as a practical machine learning research agenda, laying out five concrete problems including safe exploration and avoiding reward hacking. It became a foundational reference for safety research, and its authors included Amodei and Chris Olah, who would later co-found Anthropic.