The Reims City Hall doesn't have explosives.
Shire wanted to do it, but that's the City Hall, right in the city center.
Burying explosives under the eyes of the public would be meaningless, as the Germans would easily find out beforehand, rendering all efforts useless.
Not only would it waste precious explosives and time, it would also cause panic at the City Hall and among nearby residents, since nobody wants to live or work atop explosives.
However, this didn't stop Shire from spreading the "fake news" that "there are explosives buried under the City Hall."
The benefit is making the Germans hastily move their command from the City Hall.
At least during this time, the Germans are blank on command, even in chaos.
Hutier doesn't even know where to set up his command post.
School?
With classes suspended there and far from residential areas, it could easily be targeted for "precision elimination" by French bombers.
Residential area?
