its factories. A leading destination for immigrants from Europe, particularly Italy and Spain, from 1880 to 1930 Buenos Aires became a multicultural city that ranked itself with the major European capitals. The Colón Theater became one of the world's top opera venues, and the city became the regional capital of radio, television, cinema, and theatre. The city's main avenues were built during those years, and the dawn of the 20th century saw the construction of South America's then-tallest buildings and the first underground system. A second construction boom from 1945 to 1980 reshaped downtown and much of the city.
Buenos Aires also attracted migrants from Argentina's provinces and neighbouring countries. Shanty towns(villas miseria) started growing around the city's industrial areas during the 1930s, leading to pervasive social problems and social contrasts with the largely upwardly mobile Buenos Aires population. These laborers became the political base of Peronism, which emerged in Buenos Aires during the pivotal demonstration of 17 October 1945, at the Plaza de Mayo. Industrial workers of the Greater Buenos Aires industrial belt have been Peronism's main support base ever since, and Plaza de Mayo became the site for demonstrations and many of the country's political events; on 16 June 1955, however, a splinter faction of the Navy bombed the Plaza de Mayo area, killing 364 civilians (see Bombing of Plaza de Mayo). This was the only time the city was attacked from the air, and the event was followed by a military uprising which deposed President Perón, three months later (see Revolución Libertadora).
In the 1970s the city suffered from the fighting between left-wing revolutionary movements (Montoneros,E.R.P. and F.A.R.) and the right-wing paramilitary group Triple A, supported by Isabel Perón, who became president of Argentina in 1974 after Juan Perón's death.
The March 1976 coup, led by General Jorge Videla, only escalated this
