Little building with triangle in circle symbol

On my way to work everyday, I notice a small brick building facing the road. Above the front door is a metal sign with a triangle inside a circle and the street address.

It is not a house, and the sign and the building look fairly old. Maybe from the '50s or '60s.

Does anyone know what this building is used for?

A cold-war era old bomb shelter?

Or maybe it’s this?

I think that’s it Rico. Thank you. When I was googling, I same across that piece of jewerly on a gay-pride site.

So the building is used of AA meetings, makes sense.

Your’e very welcome.

Interesting site I googled into when I found that.

Symbols

This page has a picture of the Civil Defence logo (lower left of “radioactive fallout” poster)

I still see those signs around from time to time.

DOH!

Rather this page…

http://www.nebraskastudies.org/0900/stories/0901_0130.html