The US plunged into the worst recession since The Great Depression of the 1930s when Lehman Brothers bank collapsed, which quickly cascaded around the world.
2008 is aka 'The Great Recession'; it likely would have been much worse without govt intervention, though the targets of the help were corporations, not the average person affected by it.
The 2008 crash was the culmination of a house of cards largely enabled by deregulation that wiped out huge mainstays in America, including the auto industry. GM and Chrysler are only with us today because of massive govt bailouts. Many banks large and small failed and were absorbed into larger ones (eg Washington Mutual). The govt bailed out other banks deemed 'too big to fail' (eg Chase).
Countries were also failing over this (eg Greece, which used the euro hence was not a sovereign currency issuer and had to rely on Germany et al to assist). Severe govt spending cuts were imposed around the world, leaving the average citizen bearing the brunt of the downturn.
None of the criminal bankers that caused this crash were held criminally or civilly accountable, sparking the Occupy protests. In fact, they still got their big bonuses that taxpayers paid for. Meanwhile, average people lost their homes, businesses, and jobs.
It took about a decade to return to pre-crash economic levels. Not counting 9/11 (the effects of which changed the trajectory of modern life), this was the first 'once in a lifetime' shock for Millennials that set us back many years … just in time for a global pandemic.
There are some movies about the 2008 crash. Maybe checkout 'Margin Call'.