Heavy rains battering the Brazilian state of Rio Grande do Sul have killed 31 people, local authorities said on Friday, and the death toll is expected to rise as dozens still have not been accounted for. More than 70 people were injured and at least 17,000 were displaced in the state bordering Uruguay and Argentina, which had nearly half of its 497 cities affected, according to Rio Grande do Sul’s civil defense. In several towns, streets essentially turned into rivers, with roads and bridges destroyed. The storm also triggered landslides and the partial collapse of a dam structure at a small hydroelectric power plant. A second dam in the city of Bento Goncalves is also at risk of collapsing, authorities said, ordering people who live nearby to evacuate. “It’s not just another critical situation; it’s probably the most critical case the state has ever recorded,” Rio Grande do Sul Governor Eduardo Leite said in a live broadcast on social media on Thursday. He added that the death toll will likely climb further as rescue teams have not been able to access certain locations. President Luiz Inacio Lula da Silva traveled to the state on Thursday to visit affected locations and discuss rescue efforts with the governor.