A census held in November 1940 discovered that the majority of people in London did not use specially created shelters. The survey revealed that of those interviewed, 27 % used domestic shelters (i.e. Anderson Shelters), 9 % slept in public shelters (specially built by the local authorities) and 4 % used underground railway stations. The rest of those interviewed were either on duty at night or slept in their own homes.
Because many people preferred to stay in their own homes during the bombing raids the government decided to look for a way of protecting people in their own homes. So in March 1941 the government began issuing Morrison Shelters.