When enemy planes were spotted air raid sirens would sound. People would make their way to shelters - either communal shelters in their street or place of work, or Andersen shelters in the garden ...

The air raid warning system was developed in 1938/ ... It brought relief to countless thousands as they made their way wearily out of shelters to resume daily life.

Ullern district, Oslo. (Norwegian Directorate for Cultural Heritage/Wikimedia Commons via Courthouse News) OSLO (AFP) — Norway said Friday it wants to reintroduce mandatory construction of air raid ...