A notable recent example: the 2008 financial crisis.
In general, economic crashes after World War II have been small compared to many in the 19th century. For example it is sometimes estimated that the panic of 1819 had an unemployment rate around 20% at the height. Serious economic catastrophes have also been not as common.
I should have been more clear -- my point isn't its severity, but rather what was seen as the greatest danger to be avoided at all costs. That greatest danger was the domino collapse of the entire global financial system and it is precisely that which led the US Fed to adopt rather unconventional methods in the aftermath of the Lehman Brothers bankruptcy.
What was widely seen (correctly or not is a different and complicated issue) as the major issue was the possibility of all the big world's banks freezing up in a chain of defaults or maybe-defaults as all of them are interlinked and hold each other's debt. That didn't exist as a problem in the XIX century.
Yesterday I was using the Global Terrorism Database to check some suprisingly low figures on what percentage of terrorist acts are committed by Muslims. (Short answer: Worldwide since 2000, about 80%, rather than 0.4 - 6% as given in various sources.) But I found some odd patterns in the data for the United States. Look at this chart of terrorist acts in the US which meet GTD criteria I-III and are listed as "unambiguous":