the return of droughts, entered the depression of the 1930s, later returning to prosperity with strong government leadership. In 1928, 2000 special constables were sworn in to break a strike of dock workers. The volunteer "Citizen's Defence Brigade" had been brought in and armed to fight striking port workers, and they were housed in a camp dubbed the "scab compound". Secondary industries helped reduce the state's dependence on primary industries. The 1933 census recorded the state population at 580,949, which was less of an increase than other states due to the state's economic limitations. In 1935 Goldsbrough Mort and Company built their multi-storey premises on North Terrace. World War II brought industrial stimulus and diversification to Adelaide under the leadership of Thomas Playford. 70,000 men and women enlisted and shipbuilding was expanded at Whyalla. Adelaide's transformation from an agricultural service centre to a 20th-century city was under way. Post world war II After the war, an assisted migration scheme brought 215,000 emigrants of many European nationalities to South Australia between 1947 and 1973. Electrical goods were manufactured in former munitions factories and Holden cars were manufactured from 1948. An earthquake did considerable damage in March 1954. The Mannum–Adelaide pipeline brought River Murray water to Adelaide in 1955 and Adelaide Airport opened at West Beach in 1955. Adelaide gained a second university in 1966 with the opening of Flinders University. In 1968, a blueprint for the building an integrated system of freeways across Adelaide was released in the form of the Metropolitan Adelaide Transport Study (MATS). Bowing to opposition from the public, who feared freeways would create urban problems such as gridlocked traffic and ghettos, the Labor government under Don Dunstan shelved MATS but retained the land in case public opinion changed in the future. In 1980, the Liberal party won government on a platform of fiscal conservatism and the premier David Tonkin, deeming Adelaide road capacities sufficient for future needs, committed his government to selling off the land acquired for the MATS plan ensuring that even when needs or public opinion changed, the construction of most MATS proposed freeways would be impossible. The Dunstan Government of the 1970s saw something of an Adelaide 'cultural revival' - establishing a wide array of social reforms and overseeing the city becoming a centre of the arts. Adelaide hosted the Australian Grand Prix between 1985 and 1996 on the Adelaide Street Circuit in the