Yeah, we had that here in NYC. Every day at exactly 12 noon they would start up "Big Joe"... the massive siren powered by a Chrysler V8 engine and it would give one loud rise---fal blast and then shut down. And at least once a month they would give "Big Joe" a full workout test... a lengthy steady tone (alert warning) and then a minute or two of the infamous rise---fall (under attack) tone and then they'd shut Big Joe down. Big Joe's were mounted on public buildings, apartment buildings, school buildings, and other strategic locations. They had a huge chopper that was powered by a big V8 engine and the whole shebang was mounted on a rotating turntable.
Here is an example of a restored "Big Joe" in action...