Fallout shelter? Ah, the signs are being taken down now that they are misleading. New York City in 2017, for example.
20180807/https://en.wikipedia.org/wiki/Fallout_shelter
20180807/https://www.huffingtonpost.com/entry/new-york-city-nuclear-fallout-shleter-signs_us_5a43816ce4b025f99e18e04d?ncid=inblnkushpmg00000009
Blast doors you ask? Oh, another thing that came from the nuclear era.
20180807/https://en.wikipedia.org/wiki/Blast_shelter
So there have been a lot of media coverage about possible things that can go wrong with fallout shelters. This is not what I was thinking about, this is something else. Not the one where people go hide in the shelter and come out only many years later.
20180807/https://en.wikipedia.org/wiki/The_Shelter_(The_Twilight_Zone)