So not to detract from the tragedy at all, but I have to say this is a really, really cool article with the way you have designed the presentation as you scroll down the river moving laterally. Well done NYT.

Brazil could care less. For that matter, we don't do anything about our pending disasters. Remember the I-35W Mississippi River bridge collapse in Minnesota? Remember Three Mile Island? Let's wait until they happen then we'll do something about it.

The people are in a web. They live near the mine, it is their financial hope to make a living for themselves and their family. They know its a risk, but what other opportunities do they have. The companies know the people need the jobs, they know these people will take the risks, that they have no power to demand greater safety and regulations. The companies exploit their predicament. The Brazilians have a saying “God is Brazilian,” thinking God will help them even when they take risks. Except he doesn’t... Desculpe o povo de Brumadinho. Meu coracao e com voces.

Brazil is not alone. Industry, agriculture, and mining all leave toxic waste ponds or piles of toxic rubble that pocket our nation from sea to shining sea. Regulations meant to curb the practice or taking the wealth and leaving the toxic residues are routinely ignored for the excuse of "good paying jobs" or a "booming economy" until events like a burning Cayahoga River Love Canal make headlines. We allow wealthy patrons to create nightmares in our midst just for the sake of their greed. Now we have a President gutting the few federal regulations that were helping to force corporations and other entities to develop responsibly, and to be held accountable for the damage they create. Making America great seems to involve making America toxic for those who live there.

A Tidal Wave of Mud. You just wanted to use that headline. The real story isn't about Brazil, it's about Bezos.

I'm not a religious person, but I pray to god that these public officials reflect from this disaster and prioritize the safety of its citizens over business interest

Just want say thanks for this great write-up. The NYT keeps me aware of important news and insights in places distant from mines (Brussels and Madrid, mainly), and this matters to me.

Pay attention. Brazilian President Jair Messias Bolsonaro and Trump are amigos. Trump would happily take our country to places not unlike Brazil today. Private wealth unchecked, no enviromental regulation, lower than low taxes for the wealthy, zero worker rights, judicial system on ice, subservient legislatures, vicious attacks on independent media (Fox noise becomes official media), journalists incarcerated and disappeared, and police watching everywhere. The 20-30% of those supporting this will also be armed to the teeth. Think it can't happen here? Think again. It already is.

What is evident from this great analysis is that this disaster was foreseeable- and NOT a total surprise for the company. In the satellite image "before the dam collapsed" you can see that the dam failed in a region to the right of "dent" at the foot of the dam. Why was there this "dent", and why were further dikes set back? Undoubtedly, to minimize seepage problems underneath (as revealed by the stream on the photo "after")! Tellingly, on the image "before", you can make out a tree-less area with indications of a small spill, next to a narrow access road, about 20 yards to the right of some buildings. Something happend there before! Going back in time using historic satellite imagery (Google Earth), one can estimate that this "spill" happened some time in mid-July 2017, coinciding with the construction of the buildings nearby. A few months later in 2017, satellite images reveal evidence of widespread removal/die-off of vegetation in this area (perhaps caused by dam seepage?), followed by regrowth in May 2018 (also visible on image "before"). However, while the area is green, its vegetation is shorter than its surrounding. Clearly, something odd (seepage?) was going on at the base of the dam in recent years--and the company was aware of it--inferring from the visible activity in the area. Furthermore peculiar is that the area showed only little activity until the Mariana dam disaster (Nov 2015). Someone must have known/feared that something wasn't quite OK down there!

Feb. 26, 1972, Buffalo Creek Disaster: 125 killed, 1,000+ injured, 4,000+ homeless; approximately 507 houses, 44 mobile homes, and 30 businesses were lost, see Buffalo Creek Mining Disaster by Gerald M. Stern... When does the price of life override earnings?

'“The dam had a safety factor in accordance with the world’s best practices,” Vale said in a statement.' Interesting this thing about best practices. Clearly those "best practices" weren't good enough. People were buried by those best practices. Best practices by themselves aren't good enough. Regulations will not be good enough. People need to be willing to do what's required. The confluence of perverse incentives, negligence, malpractice and corrupt lawmaking led to this disaster, and it will lead to more elsewhere. That prevented people from doing what was required, and led to tragedy. At root, one of the main culprits is the fiduciary responsibility. Companies which operate with only the benefit of shareholders in mind will operate with a culture of not doing what is required, just as long as shareholder value is attended to. As long as the shareholders are regarded as the only stakeholders to the neglect of the community, environment, employees and customers, people will come to harm. People may die, as was the case here.

This same issue is playing out around the world. In Labrador, Canada, local communities are sleeping with live jackets under their beds due to concern about the Muskrat Falls hydropower dam built on quick clay. http://unclegnarley.blogspot.com/2017/11/terrifying-conclusion-follows-release.html Nalcor, the Canadian crown corporation has cut corners and has created a fiscal "boondoogle" according to its own executive. An inquiry is now under way to find out how this situation has gotten to this disastrous point. On February 22, 2019, Labrador Land Protector activist Marjorie Flowers and Grand River Keeper director Roberta Benefiel are scheduled to testify. The world should be watching as local activists, once again, seek to bring attention to the massive problems of megadams. www.northeastmegadamresistance.org

The Buffalo Creek Mining disaster in West Virginia is a similar story, only it occurred in 1972. Tragedy.

This is sadly a scene throughout Minas Gerais. This is murder and an unnatural disaster. Vale creates giant holes in the landscape and shows disregard for the environment. The investors, as well as the government, should hold them accountable for their lack of effort to do what is right. This catastrophe parallels what happened in Mariana and to this day little has been done to make reparations or prevent future disasters. Thank you New York Times for making the world and the investors aware of the consequences of investments without restraints and accountability.

Just because accidents like this happen doesn't mean anyone did anything wrong. Besides, we all make mistakes.

There are many direct and indirect interacting parameters to consider in trying to understand this mining dam failure. The article notes some of them, readers have contributed additional ones. The following "literary" one, often quoted by the author Samuel Beckett, merits consideration: "Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better." This article suggests that there has been inadequate learning from past failures.From "Fail(ing) again."Personal unaccountability can be as toxic as the dam's mud slide's toxic wastes. As can a population's complacency; putting up with what IS. What WAS. And, if not effectively challenged, will continue and continue.

Mining is a curse in the state of Minas Gerais. This colonial activity has been buying influence and burying lives at a high speed pace since the gold rush of the 17th century in those lands and it never stopped (only got worse). No wealth is ever left where mountains had been replaced by dams. The activity only creates desolation, fear of the powerful and of the authorities, who collude with VALE and other less famous mining companies, most of them listed at the LME, TSX, NYSE, etc. Life's worth nothing for those in (economic and political) power, especially at the municipalities where these giants operate. NYT should send reporters to Nova Lima, just 30 min from the state's capital. The city is home to one of the oldest gold mines in the continent run by a British firm, is a shanty town run by mayors that come, go and get richer and richer despite the population's misery. It is all too common and sadly will not change. This is Minas Gerais's curse.

There were no billionaires hurt in this mud tsunami.

Regulations written by the companies, not for them. A familiar claim that is heard daily in the pursuit of corporate profits. Inadequate regulatory personnel, another valid statement. Those statements describe the conditions of environmental protection, safety of the public and corporate greed in the United States today. As our government seeks to "deregulate" it is only a matter of time before those deregulation actions have adverse results.

So apologies for asking a peripheral question, but how was it that a video camera was in place, indicating that an action was expected, and yet people had insufficient warning to get out of the path? Were warnings unheeded, or was it chance that someone was there to catch video?

It's a brilliant article, but I wish the writers had spent more time detailing the toxicity of the "mud." In fact, calling it mud at all is misleading. Most mining dams contain the tailings and highly toxic residuals from cleaning off or filtering out the ore. There is sure to be massive amounts of toxic and carcinogenic heavy metals like lead, arsenic and selenium and could well be radioactive isotopes like radium-226 or uranium-238, depending on the local geology. Anything this wall of mud touched will be an instant "Superfund Site."

I guess one of the reasons for the deluge is devoid of the observance of the Brazil government. Nowadays, Brazil economic is unstable. Even the new regulation starts imposing, no one manages it. I mean there is no cost to sustain its regulations. Long years ago, in Japan, any casualty caused by exceptional development, I mean "environment disruption".

Greed is the root cause of the "dam's" collapse.

Another stunningly well done article by the NYTimes! It is evident that wealth buying gov influence is bad policy. There either has to be more independent gov regulation and/or the risks have to be shifted by lifting the corporate veil and hence they will have to buy insurance for their risks and those insurance companies are then paid and incentivized to force the companies to follow better practices.

Great presentation of the catastrophic event by NY Times reporters. Thank you. Your reporting is better than any ever done by the professional society American Society of Civil Engineers.

People created this disaster. People can avoid making another one, if that is what they choose. Theoretically new mines are switching to a dry system for storing tailings, but all of the old dams remain dangerous.

It's important to realize that Vale, the company responsible for this disaster, which was completely preventable, is the largest supplier of mineral ore in the world. The way in which Vale does business (not complying with regulations, bribing government regulators) determines the price of steel and iron, wholesale and retail, and all the products made with them, from the frying pan in your kitchen to the beams holding up your office building. This is how international capitalism works. Your 401K or other investment account might well have Vale stock. You too profit from the misery of needless death, wether you bother to take action or not. This disaster was in Brazil involving an iron mine, but commodities are extracted and streamed into profit from Indonesia, Congo, South Africa, Bolivia, etc. International capitalism seeks to maximize profit for it's shareholders, which might include you. Only strong support for candidates and parties in politics that support a strong culture of regulatory action and legal protections can ever change this. Support who ever you can vote for who speaks openly about the need for regulating business every where in every field. The financial industry, commodities, manufacturers they all are part of this pointless and unnecessary suffering. Only a culture of vigilant regulation can change this.

Typical short term benefit, ignore long term damage. Humans are not going to survive.

You should look into all the mining dam failures in the US. Not a lot of lives lost but plenty of damage to rivers.

With trump trying to destroy the environment, the US has some catastrophes to look forward to.

Alas, what happened in Brazil is just a foretaste of what's to come with global warming. They are both caused by corporate greed. With the former it's Vale and BHP. With the later it's the Koch brothers and the other fossil-fuel dinosaurs (Exxon, BP, Shell, Arch Coal, etc.). The only difference? What transpired in Brumadinho in a few seconds and claimed the lives of an estimated 154 people that had absolutely no say in the circumstances of their deaths is taking a few more years on a global scale that will certainly extinguish humanity in a slow motion demise. It is time for the American (and global) peoples to rid themselves of the self-serving criminals that threaten both innocents and future generations with their unquenchable, rapacious greed. For anybody in Miami who doubts that - you better consider the utility of an old fashioned rowboat in addition to your SUV next time there's a tidal surge because many of the coastal roads will be under water.

This is what happens when greed overrides the common good. Laws that protect the environment in fact protect the people. The US also is now eagerly degrading the environment by undermining and trivializing environmental protections. What legacy are we leaving for our grandchildren? Such a sad story.

Thanks NYT for the thorough analysis and shining some more light on what happened. Man I feel for that community!

"Tidal Waves" are generated by the movement of the moon's gravity acting upon the ocean. This deadly wave of mud was generated by stupidity. There is no lack of hard work in Brazilian mines, however there is plenty of greed and casual attitudes about life's worth. Considering the amount of rain in Brazil, it is surprising more of these events don't take place more often.

Infrastructure around the world suffers from this current lack of international law which allows plutocrats and oligarchs to drain all equity from any government, corporation, or neighborhood watch group on the planet. Stop the money laundering. Beyond three billion, the gluttonous accumulation of wealth is a disease more ominous than any historical plague. No more yachts with IMAX theaters. This place needs serious repair and maintenance for all.

Let us not forget that the US saw a similar collapse of a coal mining dam in 1972 on the Buffalo River in West Virginia. It killed 118 + people and left 4000 homeless. "Everything In It's Path" by Kai Erikson profiles this horrible story. I am fortunate to know a survivor, who as a young man did not even know if his own children had survived as he found his way through the sludge covered valley. He found his own friends and neighbor's bodies in the mud and lodged in the trees. His life is still forever shaped by this experience. The money he eventually received from a settlement by the coal company to help rebuild his home seems like a pittance when considering the life-long trauma caused by an industry without necessary oversight.

Undoubtedly these death are attributable to political corruption. Corruption that puts profits ahead of people, puts profits ahead of safety, and, puts profits ahead of the environment. Essentially, putting profits above anything and everything. Putting profits above all other considerations. Now, which political party in this country does that remind you of? And how long before the consequences of this will take a similar toll right here? The fact is, we are all slowly being buried alive by the endless corruption that the love of money, and money alone can bring. Don't think so? Just take a look outside. And realize that the "profit motive" will end up being the death of us all. "Climate change is a hoax!"... So says the biggest liars this nation ever produced. And money alone is the reason they're saying it. I wonder how many lives those lies, and liars, will eventually cost? A million lives? Two million? A hundred million? And they couldn't care less.

And there is always some rich, corrupt person who profits from the deaths of those they oversee. Since, Trump now tore up a second nuclear treaty, I don't think anything is going to get better in the near future. Sitting out elections have consequences.

What a sad story, but not surprising. In Brazil, for those not in power or rich, life is a game of chance. These mudslides remind me of the mudslides in the favelas--the hillside slums where Rio's poorest live--where houses slide down when the rains pour. And, the government has to be shamed into doing any thing to help.

As a geologist with long-time involvement in both the energy and mining industries, I must commend the NY Times for this outstanding article. What we see here is superb reportage, with excellent graphics, photos and layman-level explanations of otherwise complex subjects. It's articles like this one that keep me paying the subscription fee. . As to the subject... Tailings dams are an essential part of much mining, and there's a vast body of science and engineering on how to build them properly. Yet clearly, this Vale dam was a disaster awaiting its moment; it's horrifying and disgusting to think that there are many others out there as well. The mining industry is already feeling political and regulatory heat over tailings dams. The effects of this dam collapse will be felt far & wide. . Another angle to note is that much of the iron ore that Vale mines is sold to its number-one customer, China. Brazil's iron isn't so much building cities in Brazil, as it's going up inside buildings, bridges, etc in China. It's called "global trade," yes... But the long-term costs are not fully accounted in mere bills of lading for ore-ships crossing the Pacific Ocean. Obviously, there's an environmental legacy left behind.

Capitalism, Socialism and the in-between...An economist who served five different US administrations worried that a society which doesn't carefully navigate resource distribution across the private-public divide will be faced with this stark choice: private affluence or public squalor. Seems Brazilians are suffering daily from 'the traffic of influence inside the licensing system.' Brazil and the USA are confronted with crumbling, antiquated infrastructure. The current US administration with help from rich politicians backing these policies doubles down on promoting private affluence at the expense of public infrastructure, public health and public safety. When will it stop?

"In Brazil, given the dearth of government inspectors, companies are allowed to self-regulate, hiring independent auditors to verify dam safety through regular inspections and an analysis of written records — all provided by the company." Sounds like a Republican fantasy!

Sitting in the safe confines of my home, i am only grieve for the lost and the affected. Thank you NYTimes for this insightful article. The graphics are worth every penny in subscription! What do I get by filling my head with events and tragedies from afar? Hopefully, a greater understanding of all that binds us and an appreciation of the slippery slopes we are on, in the USofA

It is this exact situation that providing free limited liability to corporate owners creates. When the risk of a business practice is not reflected in a cost to the owners, then the owners will naturally seek to profit from that arbitrage. It's not even conscious--if something has zero cost, animals naturally use as much as possible of it. In this case, if the owners of this mining corporation had to purchase insurance to limit their personal liability in cases like this, the insurance would cost SO much, that the owners would seek to reduce the risk by... actually changing the business practices that lead to this. Limited liability is insurance for corporate owners. They should pay for that insurance, not get it for free.

That footage is absolutely terrifying. Pay attention to a country with no real regulations or safeguards against industry, and connect the dots -- since Trump took office, EPA investigations have been cut in half. Do we want to follow in Brazil's footsteps?

Our already myopic field of vision towards newsworthy events beyond our national borders continues narrowing. This horrific catastrophe seemed to occupy but a brief moment in our news feed before we were on to the next "shinny object". NO! This demands our attention, compassion and collective action. Thank you for deploying your considerable resources in providing us with so much context to an otherwise invisible tragedy.