Barra Longa village suffered a huge about of damage. Picture: Four Corners

“The mud would come and drag me down, I would come up, it would take me down again … I screamed, calling my children, calling them, but nobody answered.”

Three months after a horror mudslide swept through towns and villages in Brazil’s Gualaxo River Valley, the stories from survivors still manage to shock.

The Fundao dam, which held back more than 50 million cubic metres of mining waste, collapsed last November, unleashing a wave of mud and destruction, killing 19 people and destroying entire livelihoods, homes and villages.

Bento Rodrigues, a subdistrict of Mariana in Brazil, was flattened by a wall of toxic mud that spewed out of a burst tailings dam from a nearby mine site in the Mariana region of Minas Gerais in the south east of the country.

Unsurprisingly, the incident was labelled the worst environmental disaster in Brazil’s history.

And, while it may sound like a problem half a world away from Australia, it’s not entirely.

The waste from the huge open cut Samarco iron ore mine is half owned by Australia’s BHP Billiton, who will end up paying billions in damages.

Brazilian mining giant Vale SA owns the other half.

Bento Rodrigues from the air. Picture: Four CornersSource:ABC

In tonight’s Four Corners, reporter Ben Knight examines who is paying the real price for BHP’s mine disaster in Brazil.

Knight, who visited the area just after the catastrophe in November and again recently, examines the enormous clean up operation taking place and speaks with those who have lost everything.

Knight told news.com.au that when he first visited the disaster zone, all he could see for miles was a sea of mud.

“Not much has changed,” he said, of his most recent visit. “The clean up is huge. We are talking about mining waste ... It’s a massive undertaking.”

Knight said while BHP was taking steps to remediate the damage, nothing could bring back people’s livelihoods or their lives.

He said the mining giant had about 30 people on the ground helping with the clean up and working to rebuild people’s lives.

But he said he believed BHP could be doing more.

In this November 2015 photo, a car and two dogs are seen on the roof of destroyed houses at the small town of Bento Rodrigues.Source:AP

Knight also asks why more wasn’t done to keep people safe when evidence showed Samarco knew there were problems with the dam months before its devastating collapse.

The mud slide destroyed the village of Bento Rodrigues and, according to Knight, villagers had always been worried about the dam but had been assured it was safe.

It also extensively damaged the nearby village of Barra Longa, where people are still counting the costs, particularly those who live along the river.

“Fundao dam had problems with drainage from the beginning, “ he said.

He said police now claim the dam collapse was caused by liquefaction, or too much water in the sandy tailings, causing the eastern wall to collapse.

“It wasn’t just a leak ... it was a catastrophic disaster,” Knight said.

Police also claim Samarco’s emergency plan to warn nearby villagers of a disaster was insufficient.

Prosecutors also say new cracks appeared in the wall in 2014 and engineer Joaquim Pimenta de Avila, who designed the original dam, was called back in to inspect them.

He warned Samarco more water monitoring devices needed to be installed, but told Knight his advice was ignored.

No warnings were issued by Samarco about the impending disaster and, according to Knight, if it wasn’t for local woman Paula Alves, who rode her small motorbike through the streets, honking the horn, and screaming at people to run, the death toll would have been much higher.

Villagers had just minutes to escape the deluge. Picture: Four Corners.Source:ABC

“It happened at 3.30pm,” Knight said. “If it was 1am everyone would have died, they would have been killed in their beds.”

Police claim the disaster was partially caused by the mine ramping up production to offset the falling iron ore price.

But according to Knight it is now BHP who is facing a damage bill in the billions of dollars, and the likelihood of lawsuits for years to come.

Knight asks BHP CEO Andrew Mackenzie if the mining giant is making good on the promise to rebuild the lives and communities affected, and what responsibility it will take for the disaster.

He also questions how BHP — which had two of its own executives on the Samarco board — didn’t know about the problems with the dam.

“We’re obviously doing an investigation of all of the communications that happened during the course of the dam,” Mr Mackenzie told Four Corners. “Of course it will affect our bottom line.”

Marilene Ramos from the Brazilian Environment Authority told Four Corners that the mud wave would have killed more than just people — killing anything alive in these water systems.

Ben Knight on Copacabana Beach, Rio, Brazil. Picture: Four CornersSource:ABC

COUNTING THE COST

A BHP Billiton spokeswoman told news.com.au she did not want to comment ahead of the Four Corners special going to air.

However, in a statement issued last week, BHP said it had made progress in negotiations with Brazilian authorities for clean-up costs and damages relating to the Samarco dam disaster.

It said it had not yet reached a settlement.

Brazil’s federal attorney-general and public authorities in two states that were affected by the disaster, have asked the mining giants to set up a $US5 billion fund for clean-up costs and damages, AAP reported.

Earlier this month, BHP outlined a $US1.12 billion provision in its half-year accounts against the Samarco business, but said it was too early to estimate the full financial impact.

Meanwhile, Brazilian mining giant Vale revealed last week it lost $12.13 billion last year due to lower prices for iron ore, the sharp depreciation of the real, and the deadly mining accident.

For the fourth quarter, Vale posted a loss of $8.57 billion, nearly four times larger than in the third quarter, AFP reported.

BHP Billiton CEO Andrew Mackenzie pictured in an earlier press conference following the disaster.Source:News Corp Australia

The toxic sludge polluted hundreds of square miles as it made its way through two Brazilian states down the Doce river to the Atlantic Ocean.

Drinking water supplies were cut for hundreds of thousands of people and local fishing and tourist businesses were badly impacted.

The government is negotiating huge compensation and clean-up payments with the mine owners.

“We have worked diligently with Samarco since the beginning and we will continue to be totally committed with support to the affected regions and communities, as well as its socio-environmental recovery,” Vale said in a statement.

Prosecutors and the Brazilian government pin the responsibility squarely on Vale and BHP.

Just last week, police charged the six Samarco officials with homicide, according to Brazilian media reports, AFP reported.

According to the BBC, Samarco President Ricardo Vescovi was charged along with five other Samarco executives and one contractor.

In Brazil, homicide convictions can result in prison sentences of 12 to 30 years. Police are asking for separate sentences for all 19 deaths: 17 confirmed killed and two people listed missing.

Catastrophic Failure, reported by Ben Knight and presented by Sarah Ferguson, goes to air on Monday, February 29 at 8.30pm on ABC and iview.

Continue the conversation @newscomHQ | @benknight38

A woman throws muddy water on the facade of Brazilian mining company Vale headquarters next to a sign reading ‘How much does a life cost?’ in November last year.Source:AFP