Ask HN: Why were OpenAI, Claude, and Grok simultaneously down?

Commenters argue that Down Detector doesn't actively probe services; instead it infers outages from spikes in user searches and 'Report a Problem' clicks on its own site, comparing them against a six-month baseline. One user said Gemini was working fine throughout, suggesting the apparent mass outage may have been amplified by people checking other services after hearing about one outage.