OpenAI and Anthropic stay quiet on cause of Sept 3 outages

On the morning of Thursday, September 3, ChatGPT, Claude and Grok were all down at roughly the same time. Three of the biggest frontier AI providers hit an unusual synchronous stumble.

OpenAI, per Wired, pinned its incident on internal plumbing. "A routing error starting around 7:43 am PT on Thursday, September 3, made ChatGPT and Codex unavailable for some users across platforms," an OpenAI spokesperson told the magazine. A solution was in place by about 8:17 am PT.

xAI was blunter about location. SpaceX, its parent, said the Grok issues came from "an outage at our Memphis compute center this morning."

Anthropic's status page flagged elevated errors and, in a later update, said the "only affected models right now are Opus 4.8 and Opus 5." A spokesperson said afterward that "Claude is fully back up after an infrastructure issue caused a partial outage across Claude.ai, Claude Code, Claude Cowork, and the Claude API earlier today."

The coincidence invited an obvious question: was something shared underneath? Wired's finding is flat: "neither OpenAI nor Anthropic cited an external source in comments to WIRED" on Thursday. DownDetector reports for OpenAI peaked above 36,000 during the window. Two of the AI researchers we track posted the story the same day.

The stated causes, a routing error, a Memphis compute outage, an unspecified infrastructure issue, do not on their face line up. Whether the three events were genuinely independent or share a supplier neither company will name is what nobody is yet saying.