Presumptive GOP presidential candidate Mitt Romney faced a barrage of insults from a protester on Tuesday while taking questions at a New York City firehouse.

"Mitt Romney, you're a racist," the heckler screamed repeatedly, while Romney attempted to maintain his composure.

Unfazed, Romney continued to answer a question about a recent President Obama campaign ad that the former Massachusetts governor has claimed is an attempt to unfairly "politicize" the decision to take out Osama bin Laden. Romney has said that he wouldn't have hesitated to order the mission as well.

The protester trailed off as Romney spoke from Engine 24 and Ladder 5, a lower Manhattan firehouse that lost 11 men on September 11, but the heckling wasn't over.

"F*** you, Mitt Romney," the voice roared back, appearing to stumble over the candidate's name. Romney kept speaking.

(Video around the 35-second mark above)

Romney was also targeted earlier in the day by someone who urged him not to place the pizzas he was carrying on top of his roof, likely a reference to the now infamous story of the Republican's dog, Seamus, who once weathered a long road trip in a crate strapped to the roof of the family car.

Also on HuffPost: