A month after the iron ore mine dam collapse that killed at least 179 people in Brazil, officials passed a law banning the type of dam that failed.

The bill signed by Governor Romeu Zema impacts mining companies operating in the state, giving them 90 days to present plans to substitute the dams within three years.

Even at this late date, search crews are trying to find some 130 people who are still missing after the disaster in mineral-rich Minas Gerais state. 

"The facts are indisputable: Over 300 people died because these kinds of dams are unsafe," said Minas Gerais state legislator Joao Vitor Xavier.  "Those who chose to ignore this reality can't deny it anymore."

The dam, owned and operated by Vale SA,collapsed on 25 January.  It sent a torrent of mud down river to Brumadinho town and beyond, burying a cafeteria where Vale employees were eating, as well as an inn and several other structures.