Exactly a month after the evacuation of Dunkirk, a bomb went off at the World's Fair in New York City, killing two NYPD officers 

Over the years, there has been speculation that the bomb, which was found in the British pavilion, may have been planted by the Brits themselves 

In the weeks before the explosion, Winston Churchill sent Sir William Stephenson to New York City to set up a spy shop for MI6

At the time, the United States was still neutral in the war, and German and Allied groups in American were vying to sway public sympathies in their favor

It's been suggested that Stephenson could have been behind the bombing, so as to curry favor for the British in the war  

NYPD Lt. Bernard Whalen, who has studied the case, refused to point a finger but said: 'You could draw the conclusion that it was an inside job'