BRUMADINHO, Brazil — Two days after a torrent of mud pouring from a ruptured mining dam left at least 58 dead and 305 missing in the Brazilian town of Brumadinho, residents had to evacuate Sunday as a second dam threatened to collapse, spurring panic and outrage at what residents called a lack of accountability for Brazil’s powerful mining industry.

Sirens sounded before dawn, set off by heavy rains and dangerously high water levels at a dam at an iron ore complex owned by the Brazilian mining giant Vale S.A. Rescue workers looking for survivors from Friday’s disaster turned instead to evacuating residents to higher ground.

By the end of the day, residents were allowed to return to their homes. But for many Brazilians, this latest warning was further evidence that the system regulating the mining industry is broken, risking people’s lives and endangering the environment.

Still, few expect the rules to tighten under Brazil’s new president, Jair Bolsonaro, who promised during his campaign to restrict fines and ease regulations on mining and other industries that exploit natural resources.