GFC?
Does the earth-shaking event have to be bad? I was alive during the Apollo Moon missions. That shook things up. Too bad the photo of Earth, proving it's round, still hasn't convinced the flat-earth zealots.
It's not quite 20 years since 9/11. I would guess that most of CFC can say they lived through it. And most of us have so far lived through covid (RIP rah

).
Hm... going back... depending on your definition of whether a fetus counts as able to live through something, my mother was pregnant with me during the Cuban Missile Crisis. I was a young baby when JFK was assassinated. As for the USSR, something I read in a news article - or maybe I heard it on TV (don't recall)... there was a publishing company that produced atlases. They had just finished their latest update when the USSR disintegrated. Suddenly they had who-knows-how-many copies of newly-printed atlases that were rendered worthless.