The tailings dam, owned by Brazilian mining giant Vale, broke apart “very violently, very suddenly”, sending a massive torrent of mud over the complex where 300 mine employees were working, Vale CEO Fabio Schvartsman told a news conference in Rio de Janeiro.
The deluge rumbled on to the nearby town of Brumadinho, located southwest of the city of Belo Horizonte, cutting a swath through vegetation, farmland and roads, and impeding access to the area.
The death toll was expected to go higher, as rescue teams scoured through the big disaster zone overnight into Saturday.
Brazil’s new government led by President Jair Bolsonaro reacted to its first big emergency since taking office early this month by launching disaster coordination between the defense, mining and environment ministries and authorities in the affected state of Minas Gerais.
Bolsonaro and his defense minister were to fly over the zone on Saturday. His environment minister raced to the area late Friday.
An AFP photographer viewing the zone from the air described tractors, houses and a bridge submerged in mud, and emergency crews using earth-moving machinery to search for survivors. Television images earlier showed helicopters being used to rescue people stuck in mud.
Schvartsman called the dam break “a human tragedy, because we’re talking about probably a large number of victims — we don’t know how many but we know it will be a high number”. He said more than 100 of the mine’s employees had been located alive, but the rest were missing.
Schvartsman, who had his two-year term renewed just last month by Vale’s board, said the it had been an “inactive dam” that was in the process of being decommissioned that burst apart. Its contents — tailings, or mining byproducts mixed with water — cascaded into another dam, which overflowed, he said.
The liquid, brown mass — reportedly quantified at one million tons by Ibama, Brazil’s environmental protection agency — barrelled on towards Brumadinho, population 39,000, but did not deal it a direct hit.
Shares in Vale plummeted eight per cent in New York trading Friday. The Sao Paulo stock market was closed for a holiday.
Friday’s disaster recalled trauma from a 2015 dam break in a different part of the same state of Minas Gerais, in Mariana, in which 19 people died. That accident three years ago released millions of tons of toxic iron waste along hundreds of kilometers (miles), causing what is considered the country’s worst environmental disaster. Vale was joint operator of that dam, along with the Anglo-Australian group BHP.
An AFP photographer said police had blocked access roads to Brumadinho on Friday after the disaster. Civil defense officials said people living in low-lying areas in the town had been evacuated.
Vale issued a statement saying it had set up shelters for Brumadinho residents left homeless.
Brumadinho’s municipality issued an alert on social media warning residents to move away from the Paraopeba river that the dam had been holding back.
The town is best known to tourists for Inhotim, an outdoor contemporary art museum, which was evacuated as a precaution. The venue receives 35,000 visitors a month. (AFP)