It used to be back in the 1950s-1960s during the Cold War that the Sedgwick County, KS EMA insisted that every public school building had at least one Thunderbolt, either mounted on a pole in the field behind the school (that was the most common installation) or on top of the building.
This quote from douro20 brought back memories! The city of Nashville once had a system of Thunderbolts. I don't know just when it was installed; would speculate sometime in 50s.
There was one on a pole behind the Overton High School building (my alma mater). Well do I remember the every Wednesday noon tests during the Cold War/Cuban Missile Crisis days of the early 60s.
There were Thunderbolts at other schools around town, along with 2 atop buildings uptown. These sirens were disconnected sometime in the 80s; most of them have been taken down now.
A few years ago the city installed 70 of the ATI sirens on city property; many of them at schools. There's one at Crieve Hall School, about a half mile from my house.
The system is tested on 1st Saturday of the month at noon. Many Saturdays I don't hear it at all. If the wind is blowing the right direction I can hear it.