I mostly remember AWS S3 outages, usually limited to a region, but the one in 2017 was supposed to be a regional update (US-EAST-1 region), brought down like a half of AWS, because they depended on S3 in US-EAST-1 [1]

Note that even the intended configuration change was designed to be Regional, not just limited to one AZ.

https://aws.amazon.com/message/41926/