Why were many favelas torn down in Brazil a few years ago?

Largely ignored by city and state government for much of the first half of the twentieth century, the favelas began to attract political attention starting in the mid-1940s. During this period, populist politicians ascended to power on both the national and local stage championing a platform of poverty alleviation and national modernization. A central part of their program was providing modern, sanitary, public housing units as an alternative to slums, which were thought to breed not only disease

Answer:The history of the favelas of Rio de Janeiro begins in the final years of the nineteenth century as Brazil transitioned from an empire to a republic. As the nation continued to undergo dramatic political changes throughout the course of the twentieth century, the slums of its second-largest city grew in size and number, in turn experiencing significant changes of their own. Initially, these communities were loosely incorporated squatter settlements that sprang up organically in order to house internal migrants and itinerant laborers. As they became more numerous and increasingly populated by a burgeoning urban underclass, favela residents began to organize internally, forming associações de moradores, or residents' associations. These organizations served as forums for deliberating matters of community governance, in addition to acting as liaisons between favelados (favela residents) and the prefeitura (city hall). Since the city and state governments failed to extend many public services to the favelas, community members, led by their local associations, banded together to provide sanitation, medical care, and transportation to their friends and neighbors.