A failure in Microsoft Azure’s East US region caused simultaneous elevated error rates across three major AI platforms for roughly 90 minutes to two hours. ChatGPT and Codex, Claude, and Grok were all disrupted, generating tens of thousands of user reports, while Microsoft Copilot was also affected; Google’s Gemini was largely unaffected because it runs on independent infrastructure. None of the companies involved has published a financial estimate of the disruption’s cost.