Not less than 13 folks have been killed and 21 are lacking after heavy rains drenched southern Brazil, prompting a state authorities to ship rescue helicopters looking for stranded residents, the authorities mentioned on Thursday.

The torrential rains that poured over the state of Rio Grande do Sul in current days had been effectively above regular for this time of yr, in line with consultants.

Within the final 4 days of April, the state obtained about 70 p.c of the precipitation it usually data for your entire month, in line with Nationwide Institute of Meteorology information analyzed by The New York Occasions.

The rains swelled rivers throughout the state’s low-lying central valley area, flooding cities, inflicting a bridge to break down, blocking roads and triggering mudslides. One city, Canudos do Vale, was left remoted with no electrical energy or communication. Within the city of Candelária, residents awaited rescue helicopters on the roofs of their flooded properties.

Practically 10,000 folks have been compelled to flee their properties, the civil protection company in Rio Grande do Sul mentioned in an announcement. The disaster prompted Grande do Sul’s governor, Eduardo Leite, to declare a state of emergency late on Wednesday.

“We’re experiencing, in Rio Grande do Sul, the worst second — the worst catastrophe in our historical past,” Mr. Leite mentioned at a information convention on Wednesday. “And sadly, it is going to worsen.”

Authorities have struggled to succeed in remoted residents, with search-and-rescue groups unable to journey to some areas due to excessive river ranges and heavy flooding. With nowhere to land, some helicopters have used winches to drag up residents from flooded areas.

“We will be unable to make all of the rescues,” Mr. Leite mentioned on Wednesday.

Meteorologists warned that extra rain was probably on the way in which within the coming days, which may additional complicate rescue efforts.

The nation’s president, Luiz Inácio Lula da Silva, who was to go to the area on Thursday, promised that federal businesses would “be part of the efforts of state authorities and municipalities to get via this tough time.’’

Final yr, 37 folks had been killed in the identical area of Brazil by torrential rains and punishing winds attributable to a cyclone.

The nationwide climate institute mentioned the area was reeling from the results of a pure climate phenomenon generally known as El Niño, which may set off heavy rains in Brazil’s southern areas, whereas at similar time inflicting drought within the Amazon rainforest.