Lyn,
The reason that more people did not lose their lives was due to the foresight of the government in providing the Anderson garden shelters and the Morrison indoor shelters. In addition public shelters were built all over the place so that in the raids the people could take shelter.
Sadly sometimes the shelters were hit and that was that. Many people of course had to be out and about and there were times when the warning system was not as good as it should be and raiders struck before the air raid sirens sounded.
Chris (Old Boy)