If you were a resident of Winnipeg who missed the Tribune's front page headlines in the run up to February 19, 1942, then you were in store for a terrifying surprise. The city had planned a mock Nazi invasion as a means to drum up Allied support and money for the war effort - and scaring its residents was the intended outcome.

Local child Diane Edgelow was not prepared for the terrifying shock of her life when she was ordered by her mother to retrieve a loaf of bread on the morning of February 19, 1942. She crossed the bridge into downtown Winnipeg, Canada before she was confronted by German Nazi soldiers.

'They were guarded by German soldiers; they seemed to be everywhere,' she recalls. 'I was so scared.' She paid for the bread and was given a German Reichsmark as change.

'No one in our house would read the paper,' said Edgelow in an interview with Legion Magazine. 'I don't think my mom would have sent me down to the store if she knew there were going to be soldiers dressed like that. Maybe I wouldn't have been so scared if I had been told before.'

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Canadian authorities staged a Nazi invasion of Winnipeg on February 19, 1942 in an effort to boost lagging sales of war bonds - even renting German uniforms from a Hollywood supplier and arresting Canadian officials during the full-fledged mock event, which was labeled If Day; here, authorities taken from government buildings are marched to an uncertain fate

During the extensive exercise, the Union Jack was replaced by a Nazi swastika flag; the 'invasion' also included notices and posters plastered around the city and a book burning outside of a library - using materials the library had already planned to destroy

During the event, the 'Nazis' were actually members of the Young Men's Section of the Winnipeg Board of Trade - while Canadian forces were comprised of 3,500 soldiers from active and reserve forces. The 'Nazis' were instructed to harass civilians during the exercise, just as a real-life invasion would disrupt and scare Winnipeg residents

It became known as 'If Day,' an elaborate publicity stunt to promote the purchase of Victory Bonds spearheaded by prominent Winnipeg businessman, J.D. Perrin. This week marks the 77th anniversary of the event.

The operation involved 3,500 Canadian troops and reserve soldiers to stand in as 'Allied soldiers' - making it the largest military maneuver ever seen in the province, far outshining the region's 1885 North-West Rebellion.

Volunteers from the Young Men's Section of the Board of Trade stood in as 'Nazi' soldiers; they were armed with rifles from the Canadian Armed Forces and outfitted in uniforms sent from Hollywood that were complete with jackboots, badges, belts, and helmets.

Residents of Winnipeg, (which was renamed Himmlerstadt for the day) were jarred out of slumber by air raid sirens and blackout orders in preparation for a Nazi Invasion. Canadian Air Force planes were repainted with the German Luftwaffe insignia to begin their fake aerial blitzkrieg on the city. Thirty anti-aircraft tanks fired blanks at the fighter planes overhead, strengthened by anti-aircraft gunners that mounted the tops of buildings downtown.

In order to stall enemy advance, main bridges across the city were 'destroyed' by coal, dust and dynamite for a high-impact effect which generated a deafening explosion of river debris in plumes of smoke.

Local radio stations broadcast updates of the battle as smoke, bomb explosions and crackling gunfire plagued the streets. The first fake casualty was reported at 8:00am; army hospitals were set up at strategic points throughout the city to dress wounded soldiers.

The Winnipeg Tribune published a mock newspaper on If Day called Das Winnipegger Lugenblatt; it was full of Nazi propaganda but also included editorials from local expatriates living in Canada who described how their home countries had been ravaged by German occupying forces. The Tribune had also warned residents two days beforehand about the mock invasion with front-page stories; but not everyone read them, and many people were taken aback, confused and alarmed by the sudden military presence on their streets and in their homes, churches and schools

The day's events included a military 'inspection' by occupying 'Nazi' forces. In addition, In order to stall enemy advance, main bridges across the city were 'destroyed' by coal, dust and dynamite for a high-impact effect which generated a deafening explosion of river debris in plumes of smoke

This mock notice circulated to Winnipeg residents on If Day announced the disbanding of the Boy Scouts and Girl Scouts, as well as imposing a 9.30pm curfew and banning public gatherings. While many other North American towns and cities staged mock invasions, Winnipeg took it particularly seriously, with meticulous attention to detail - despite the fact that the possibility of a Transatlantic assault was remote

By 9:30am, the Allied forces surrendered Winnipeg to the Nazis. The local radio station had been commandeered by the Wehrmacht and its announcer was detained. Hitler's voice was broadcast throughout the city as Nazi soldiers marched in their regimented gait down 'Hitlerstrasse' (Portage Avenue) for their Victory Parade. The scene was eerily akin to the Nazi takeover of Paris just two years beforehand.

All this might have been enough to prove the point, but organizers of 'If Day' left no stone unturned. The occupation continued well into the evening: books were burned outside of Carnegie Library, and homes and stores were looted by the fake troops that conducted rough searches and harassed civilians. City officials were jailed and the Union Jack at Lower Fort Garry was replaced with the swastika.

'I caught a glimpse of the burning books,' says George Hoffman, then a 19-year-old private in the Army. Talking to Legion Magazine in 2017, Hoffman admits that he was alarmed at first. 'But then I read in the paper that these were books the library was going to destroy anyway, so they were used to build this bonfire. But a lot of people didn't know what was going on.'

Perhaps the only shortcoming in the planning of 'If Day' was that the flimsy Nazi costume rentals were no match for the bone chilling -8 degree Fahrenheit freeze. The recreations were a far cry from the Hugo Boss designed Waffenrocks that clothed the backs of Hitler's henchmen. So instead, the mock Nazi soldiers seized buffalo fur coats from the police station during their occupation. (Interestingly, real Nazis had the same sartorial problem when their uniforms ill prepared them for the Russian winter.)

Surprisingly, it was only three years before 'If Day' that 500 locals had attended a gathering hosted by the local German consulate in January 1939. The evening was filled with Nazi salutes, speeches, framed portraits of the Fuhrer and swastika flags while Mennonite choirs sang Nazi songs.

In the end, J.D. Perrin's $3,000 terrifying stunt was a huge success. His simulated Nazi takeover raised far more than the goal of $45 million in bond sales - $47,073,500 for the wartime effort.

'A lot of people were very uneasy and quite intimidated about this thing,' said Hoffman to Legion Magazine. 'Maybe it made them think that it could happen here. They didn't know how far these Nazis would go. Would they rough the population up? Of course us younger guys had visions of going over and fighting them but at the same time you were a little apprehensive.'

If Day's mock causalities were no comparison to the devastating news that two Winnipeg families received on the same day, however. Albert Pryor and James Condie, had been killed when their warship was torpedoed in the North Atlantic and millions more would die before WWII finally ended in 1945.

And, in a strangely coincidental turn of events, on the same day that Winnipeg was carrying out its exercise, there was an Axis attack on one of Canada's Commonwealth allies. Japanese aircraft carried out a bombing raid on Darwin, Australia, further fueling fears of long-distance attacks. Such incidents, combined with the mock invasion, helped bolster anti-Nazi feelings in Canada, and the money flowed into bonds - the 'fake' operation a clear (if intimidating) success.

While If Day was staged to increase support for the war and war bonds, Winnipeg just three years beforehand had been the site of a Nazi rally - but the intimidating exercise appeared to definitely sway opinion, with funds raised surpassing the initial $45million goal and totaling $47,073,500 was raised (amounting to more than $650million today)

Manitoba premier John Bracken, pictured, was arrested by the 'invading' forces, along with several other government ministers, Winnipeg Mayor John Queen, city aldermen and the city clerk. Instead, a Nazi leader named Colonel Erich von Neuremburg was put in charge, and the city was renamed Himmlerstadt

'A lot of people were very uneasy and quite intimidated about this thing,' George Hoffman, who participated as a 19-year-old private with the 1st Cavalry Division Service Corps, told Legion, Canada's military history magazine, in 2017. 'Maybe it made them think that it could happen here. They didn't know how far these Nazis would go. Would they rough the population up? Of course us younger guys had visions of going over and fighting them but at the same time you were a little apprehensive'