(CNN) -- Flooding in Brazil's Santa Catarina state has left at least 50 dead and more than 20,000 homeless, the state news agency reported Monday.

The rain-fueled flooding in southern Brazil affected 1.5 million residents and cut off five cities -- Rio dos Cedros, Pomerode, Itapoa, Garuva, and Benedito Novo -- from the rest of the nation, Agencia Brasil reported.

Civil defense officials said patients at the Santa Ines Hospital in the beach resort city of Balneario Camboriu were moved to another part of the hospital, the news agency said.

Joao Paulo Kleinubing, the mayor of Blumenau, declared a state of public calamity Sunday night, Agencia Brasil said. He had declared a state of emergency on Saturday. iReport.com: Are you there? Share stories, images

Officials were sending two helicopters to Blumenau on Monday to help victims.

Aid also was being sent to the states of Rio Grande do Sul and Parana, which also have been hit hard by flooding, Agencia Brasil said.

Elsewhere, video footage from CNN affiliate TV station Record Internacional showed that heavy rain in Sao Paulo caused part of a roadway to collapse.

All About Brazil • Floods