The 2008 financial crisis was caused by the repeal of regulations separating commercial and investment banking (Glass-Steagall Act). This led to excessive risk taking, complex financial products, lack of oversight, and the housing bubble. The crisis started with the collapse of the housing market but was exacerbated by factors like credit default swaps, subprime lending, and the use of leverage. Proper regulation and accounting standards are needed to prevent future crises and ensure stability and transparency in the financial system.