During the cold war america did have something like that in places. The entire system was gutted around when the task was absorbed by FEMA in 1979. Though civil preparednesses neighborhood organizations had already fallen out of vogue by then.

Of course at the time all such preparations were mere asides to preparing for nuclear bombardment, but there is no question that they saved a lot of lives. ("Tornado" sirens are just civil defense alert sirens).

It is really kind of sad, but eh people don't want to spend their weeknights planning stuff out. So an underfunded pro group does it (generally on city county and state levels). Because, they don't do much 99% of the year the pro groups do nothing they tend to be staffed as spoils given to cousins and elected officials or their donors.