Europe's Crisis Spooking U.S. Markets

In a reversal of the old saying, this time, it's Europe's cold that has America sniffling. Britain's top financial officer says this is the "most dangerous time for global economy since 2008."

Investor worries over the exposure of U.S. banks to European debt are part of the reason Wall Street has seen steep drops recently — with U.S. bank stocks particularly hard hit. So how bad is Europe's crisis and how much damage can it do to the American economy?