early 1960s, French repatriates from Algeria swelled the city's population. In 1963, Toulouse was chosen to become one of the country's eight “balancing Metropolis”, regaining a position among the country's major cities that it had always had, but lost in the 19th century. The French state then encouraged the city's specialisation in aeronautics and space activities, sectors that had experienced strong growth in recent decades, fueling economic and population growth. On 21 September 2001, an explosion occurred at the AZF fertiliser factory, causing 31 deaths, about 30 seriously wounded and 2,500 light casualties. The blast measured 3.4 on the Richter scale and the explosion was heard away. In 2016 a territorial reform made Toulouse the regional prefecture of Occitanie, the second largest region in metropolitan France, giving it a role commensurate with its past as a provincial capital among the most important in France. Population The population of the city proper (French: commune) was 498,003 at the January 2020 census, with 1,470,899 inhabitants in the metropolitan area, up from 1,268,438 at the January 2009 census. Thus, the metropolitan area registered a population growth rate of +1.36% per year between 2009 and 2020, the third-highest growth rate of any French metropolitan area larger than 500,000 inhabitants in France, after Montpellier and Bordeaux, although it was slightly lower than the growth rate registered between the 1990 and 2009 censuses. Toulouse is the fourth most populated city in France, after Paris, Marseille and Lyon, and the fifth most populated metropolitan area after Paris, Lyon, Marseille, and Lille. Fueled by booming aerospace and high-tech industries, the Toulouse metropolitan area's population grew by 57.3% between the 1990 and 2020 censuses (within its 2020 borders), which means +1.52% per year on average during those 30 years, compared with a growth of 15.3% for metropolitan France between 1990 and 2020, i.e. +0.48% per year. This was the second-highest population growth of any French metropolitan area larger than 500,000 inhabitants (only the Montpellier metropolitan area grew more than Toulouse between 1990 and 2019). The Toulouse metropolitan area reached 1,470,899 inhabitants in January 2020, and stood as the 5th most populated metropolitan area in France, behind the metropolitan areas of Paris, Lyon, Marseille, and Lille, but ahead of the metropolitan area of Bordeaux, which the Toulouse metropolitan area passed in population in the 1990s. A local Jewish group estimates there are about 2,500 Jewish families in Toulouse. A Muslim