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All issuesVolume 342, Issue 3IT NewsCxO

The Cloud Outage That Should Terrify the CIO

InfoWorld, Friday, September 18th, 2026

ChatGPT, Claude, Grok and Copilot all degraded together on one Azure region failure, exposing concentrated dependency risk.

On September 3, a failure in Microsoft Azure's East US region degraded or darkened ChatGPT, Claude, Grok and Microsoft's own Copilot within roughly 90 minutes.

Downdetector logged more than 37,000 reports for ChatGPT alone, and combined counts passed 66,000 before mitigations landed. What made the event notable was not scale but simultaneity: three fiercely competing AI labs that each spend billions differentiating their models all buckled at once because they shared a regional dependency.

Gemini stayed largely upright because Google runs it on its own vertically integrated stack, which the author calls architecture rather than luck.

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