1959 - Work secretly began on the Emergency Government Headquarters outside Ottawa, Ontario. It was known officially as Canadian Forces Station Carp and unofficially as the 'Diefenbunker', named for Prime Minister John G. Diefenbaker who authorised the construction. It was an underground four story 100,000 cubic foot building with five foot thick walls which could support 535 people for 30 days. In 1998 it was declared a Cold War National Historic Site and opened to the public.