Between January 11-12, 2011, torrential rains in Brazil's Rio de Janeiro state caused devastating floods and mudslides that killed over 900 people and left over 17,000 homeless. The city of Teresopolis was hit hardest by the floods and mudslides, which were worsened by deforestation and a lack of drainage infrastructure. While rains are common during the Brazilian summer, experts noted that the scale of the disaster was exacerbated by a lack of preventative measures and urban planning in poorer mountainous regions prone to flooding.