Well supposedly, this is the last test of the city of Sioux Falls outdoor warning siren system as they will resume next year.
I recorded this audio of two 2001-130's halfway in between them
MP3: https://soundcloud.com/user-774625703/f ... 39ac4beb68
This Federal Signal 2001-130 was installed within the past year and this potent video of this relatively new 130 sounds alert
Video: https://youtu.be/7NeJhXM5faY
Enjoy