The Halifax Explosion of 1917 is a defining event in the Canadian consciousness, yet it has never been the subject of a sustained analytical history. Astonishingly, until now no one has consulted the large federal government archives that contain first-hand accounts of the disaster and the response of national authorities. Canada’s recently established navy was at the epicentre of the crisis. Armstrong reveals the navy’s compelling, and little-known, story by carefully retracing the events preceding the disaster and the role of the military in its aftermath. He catches the pulse of disaster response in official Ottawa and provides a compelling analysis of the legal manoeuvres, rhetoric, blunders, public controversy, and crisis management that ensued. His disturbing conclusion is that federal officials knew of potential dangers in the harbour before the explosion, took no corrective action, and kept the information from the public.