million psychiatric patients. Winston Churchill told Parliament in 1934, "We must expect that, under the pressure of continuous attack upon London, at least three or four million people would be driven out into the open country around the metropolis". Panic during the Munich crisis, such as the migration by 150,000 people to Wales, contributed to fear of social chaos. The government planned the evacuation of four million people—mostly women and children—from urban areas, including 1.4 million from London. It expected about 90% of evacuees to stay in private homes, conducted an extensive survey to determine the amount of space available and made detailed preparations for transporting evacuees. A trial blackout was held on 10 August 1939 and when Germany invaded Poland on 1 September, a blackout began at sunset. Lights were not allowed after dark for almost six years and the blackout became by far the most unpopular aspect of the war for civilians, even more than rationing. The relocation of the government and the civil service was also planned but would only have occurred if necessary so as not to damage civilian morale. Not only was there evacuation over land, but also by ship. The Children's Overseas Reception Board was organised by the government to help parents send their children overseas to four British Dominions — Canada, Australia, New Zealand, and South Africa. The programme evacuated 2,664 boys and girls (ages 5 - 15) until its ending in October after the sinking of the SS City of Benares with the loss of 81 children out of 100 on board. Much civil-defence preparation in the form of shelters was left in the hands of local authorities and many areas such as Birmingham, Coventry, Belfast and the East End of London did not have enough shelters. The unexpected delay to civilian bombing during the Phoney War meant that the shelter programme finished in June 1940, before the Blitz. The programme favoured backyard Anderson shelters and small brick surface shelters. Many of the latter were abandoned in 1940 as unsafe. Authorities expected that the raids would be brief and in daylight, rather than attacks by night, which forced Londoners to sleep in shelters. Communal shelters Deep shelters provided most protection against a direct hit. The government did not build them for large populations before the war because of cost, time to build and fears that their safety would cause occupants to refuse