In 1942, the Minneapolis Police Department built and configured the Air Raid Control Center which was subsequently staffed and managed by municipal employees.
The Air Raid Control Center was in full use during the city-wide drill of September 11, 1942. The photograph above depicts a victim from a simulated bombing scenario.
Here is the actual Blackout Procedure Manual used by then Captain (formerly Chief) Frank Forestal in 1942.
Photograph above from the Minneapolis StarTribune of September 11, 1942