Story highlights The spot is created by a little-known super PAC called the Fifty Second Street Fund

Hillary Clinton's campaign has similarly raised the specter of a Trump nuclear attack

Washington (CNN) A new super PAC formed by former Democratic presidential candidate Bill Bradley is funding a dramatic ad warning that Donald Trump's election could usher in an era of nuclear warfare and kill more people than live in Ohio's largest city.

"One nuclear bomb can kill a million people. That's more than all the men, women and children living in Columbus, Ohio," says the ad, which debuted in that city and others in the state on Monday

Mushroom clouds from nuclear bombs interrupt a quiet cloudless day and scenes of debris fill the screen -- just before a clip of Trump questioning America's reluctance to use the warheads.

"Why are we making them?" he says in a clip of an interview.

That's when another explosion appears.

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