Dot com crash.
9/11
Subprime mortgage crash
Trump and Iran almost start WW3
Covid.
Oh-god-interest-rates-are-a-thing crash. (Current)
Israel and Russia seem to be dead set on WW3. (Current)
Don't worry they'll never default, as they keep printing more money (they should have defaulted decades age, but keep rasing the borrowing ceiling). But they will go through hyper inflation soon enough... That will be wild.