Who's to blame for Bank of America's (BAC 0.14%) epic meltdown following the financial crisis? Analysts and commentators like to blame it on Countrywide Financial, a once-leading mortgage originator that Bank of America acquired in 2008. But is this letting Bank of America off the hook?

While it's certainly true that Countrywide has cost the nation's second largest bank by assets tens of billions of dollars, what's also true is that Bank of America's own operations prior to the financial crisis are just as responsible for its current condition. More specifically, the single-biggest culprit behind the bank's ongoing travails was its own credit card division.

As Motley Fool contributor John Maxfield discusses in the video below, losses from credit cards alone cost Bank of America more than $60 billion in the years between 2008 and 2010. By even the most liberal estimates, this is at least on par with a final tally of the bank's Countrywide-induced mortgage losses.