Hank Paulson on the 2008 financial crisis   

Former U.S. Treasury Secretary Hank Paulson describes the moment he knew Lehman Brothers’ fall meant the global financial system was at risk.

Watch the video above for an in-depth conversation between CNBC’s Andrew Ross Sorkin and Paulson about a historic week on Wall Street.

The CNBC Original “Crisis On Wall Street: The Week That Shook The World” premieres Wednesday, 10 p.m. ET/PT.