(CNN) Martin O'Malley said it was "pretty shameful" for Democratic presidential front-runner Hillary Clinton's to invoke the 9/11 attacks to deflect criticism at a debate about her relationship with Wall Street.

In an interview with CNN's "New Day," the former Maryland governor and Democratic presidential candidate was asked about Clinton's comments and the round of applause she received afterward.

"I thought that moment, frankly, was pretty shameful. I don't believe that the people watching were applauding the notion that Secretary Clinton was pumping up the smoke screen and wrapping herself in the tragedy of 9/11," O'Malley told CNN's Alisyn Camerota. "I don't think they saw that as something appropriate to do — to mask her coziness and her closeness to Wall Street and all of the architects of the crash of 2008."

At the Democratic debate Saturday night, Clinton made the comments in response to an accusation that she's too cozy with Wall Street.

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