Thanks to meteorologist Rob Dale for posting this document outlining the installation if air raid sirens.
It goes into their use and theory for warning of Japanese air raids during WWII. Of course, these are the sirens that morphed into "tornado" sirens in the central United States.
I always thought it was silly to install air raid sirens in the central U.S. because Japanese planes didn't have the range to reach places like Kansas City, St. Louis, Chicago or Wichita. But, perhaps, I was wrong. Watch video starting at about 1:15.
While George's humor is great, the sirens -- intended for use by people outdoors as a signal to go inside to get more information -- still play an important role in the integrated tornado warning system.