What's the Montparnasse Crash of your profession/area of expertise? I mean something that went so egregiously wrong that it had never happened before (and probably never since).
This was a very localized train wreck, but during my chaplain residency we were told a cautionary tale about a resident from a previous year who became so overcome with pity for an intubated and unconscious patient in the ICU that she climbed into bed next to him to snuggle him. Boundaries!
The Therac-25 radiation therapy machine in the 1980s ☢️
It’s going on at WordPress/Automattic right now.
Digitisation. To this day, the paper copy is often destroyed during the process (spine sliced off so pages can go through the automated hopper). But in many big libraries no one is checking to make sure each page is actually captured legibly, and so much stuff has been lost, leaving a shitty ghost.
Katrina
I was a developer/programmer with Flash/actionScript since the get-go. And Steve Jobs basically went and killed it. 'Cos it wasn't an Apple thing. #thebastard ...I ended up in Retail. (Which is, I have to say, a pile of fun, even if the money's no good.) The End.
The utter and spectacular crash of Barings Bank. Not playing the error account is one of the first things you learn when you learn about the stock market, and BOY HOWDY there's a good example as to why. (And a fun, if not entirely accurate, movie starring a young Ewan McGregor, so there's that.)
It happened this year! The US Dept of Ed made “improvements” to the financial aid application. Screwed it up so badly the applications usually delivered in October didn’t get to universities until mid-March. Many students in need had no idea of costs until after they had to decide on a college.