The irony here is that this is basically a mirror of what happened at AOL on August 7th, 1996. See: https://www.theregister.com/on-prem/2018/04/16/i-crashed-aol...

I was the Sr. Internet Mail Administrator at AOL at the time, and this article was what The Register wrote based on what I had submitted to them. They made a few changes. I know they were trying to protect my identity, but I think they also wanted to make it a better story.

For us, everything started with a planned downtime to upgrade the main core router for the entire service. We had the best network engineers in the business, but even they can make a mistake. And they did. And then there was a whole domino effect of events that followed.