The following script is from "King of Coal" which aired on March 6, 2016. Anderson Cooper is the correspondent. Katherine Davis, producer.
In December, for the first time in U.S. history, a CEO of a major company was convicted of a workplace safety crime. His name is Don Blankenship and he was once known as the "King of Coal." The company he ran, Massey Energy, owned more than 40 mines in central Appalachia, including the Upper Big Branch mine, located in Montcoal, West Virginia, a state where coal is the dominant industry.
In 2010, the Upper Big Branch Mine was the site of the worst mining disaster in the U.S. in 40 years -- the kind of accident that isn't supposed to happen anymore. It was just after 3 o'clock on April 5, when a massive explosion tore through miles of underground tunnels, killing 29 miners. Prosecutors accused Don Blankenship of ignoring mine safety laws and fostering a corporate mentality that allowed the disaster to occur.
Stanley Stewart: It was tremendous. I'm no expert but just from what I know of what happened and the things that were torn up in there, it had to be like an atomic explosion.
Stanley Stewart worked at the Upper Big Branch mine for 15 years. He was 300 feet underground and had just started his shift when the explosion occurred.
Stanley Stewart: I felt a little breeze of air coming from inside. And I said "That's not right." Well then it got harder and we just took off running to the outside, and looked and you could see the whoosh just keep coming and coming. Seemed like for somewhere between two and four minutes. And one of the younger guys said "Hey, what happened?" And I said, "Buddy, the place blew up."
The explosion occurred 1,000 feet underground and nearly three miles inside the mine. These photos, taken by the Mine Safety and Health Administration, have never been seen before, and show the force of the blast. Flames moving at more than 1,500 feet-per-second shot through more than two-and-a-half miles of underground tunnels. Investigators believe the blast was caused by a spark that ignited methane gas that had built up due to inadequate ventilation. Highly flammable coal dust that had been allowed to accumulate throughout the mine fueled the explosion.
Stanley Stewart: It was an early 1900s type of explosion. Conditions should never have existed for that to take place.
Stewart was there when some of the 29 miners he'd worked side-by-side with for decades were brought to the surface.
Anderson Cooper: What kind of condition were they in?
Stanley Stewart: Their faces were very black and it smelled like dynamite. I'll never forget that smell.
The miners ranged in age from 20 to 61. Most were fathers. A third were killed instantly.
Robert Atkins, a former coal miner, and his wife Shereen, lost their son Jason, who was at the end of his shift and was heading toward the mine entrance, when he was overcome by toxic fumes.
Shereen: The coal dust was so bad that it carried, it ignited all the way (crying), and took our son's life who was almost out of the mines.
Gary Quarles, a third-generation coal miner, lost his only child Gary Wayne, who left behind two children.
Gary Quarles: They lived right beside of us. And, at times, we thought that wasn't a good thing for that to be like that. And then after he...after he got killed, I said that was a good thing.
Gary says he and his son never talked about safety issues in the mines but Gary knew all about Massey because he had worked there as well.
Gary Quarles: I knew how they operated. They didn't know nothing but to lie, cheat and outlaw. That's the way they done things.
Steve Ruby: This was a coal mine and a company that was - it's not an exaggeration to say - run as a criminal enterprise.
Assistant U.S. Attorney Steve Ruby led the prosecution against Don Blankenship along with U.S. attorney for West Virginia, Booth Goodwin.
Booth Goodwin: This could be likened to a drug organization and the defendant was the kingpin.
The defendant, Don Blankenship, had for decades been one of West Virginia's most influential and powerful figures. The CEO of Massey Energy, the largest coal producer in Appalachia, he employed 5,800 people and operated more than 40 mines. Blankenship wouldn't do an interview with 60 Minutes but prosecutors say for years he condoned and tolerated safety violations for the sake of profit.
Steve Ruby: Right up, until the time the Upper Big Branch mine blew up, that was the way the company ran, because everybody understood that was the way Don Blankenship wanted it run.
Anderson Cooper: That was the corporate mentality that he instilled in his company?
Booth Goodwin: Right. That was the culture that existed.
Anderson Cooper: Profits over safety.
Booth Goodwin: Profits over safety. He set the tone. He set the corporate culture.
Despite receiving daily reports of the high number of safety violations, prosecutors argued Blankenship did little to correct them because Upper Big Branch was a big moneymaker for Massey, earning more than $600,000-a-day, and Blankenship's pay was directly tied to every foot of coal mined. In his last three years at Massey, Blankenship's total compensation was more than $80 million.
Steve Ruby: The men and women that we talked to who worked in this mine said that it was absolutely understood, it was expected that if you worked at that mine, you were going to break the law in order to produce as much coal as possible, as fast and as cheaply as possible.
Bobbie Pauley: Everything was produce, produce, produce. It didn't make any difference of the dangers. It didn't make any difference if you had to take shortcuts. It was all about put the coal on the belt.
Bobbie Pauley was the only female miner at Upper Big Branch. She wasn't working the day of the explosion but her fiancee Boone Payne was. He died in the blast. Bobbie says she and Boone worried every day the mine was an accident waiting to happen.
Anderson Cooper: Everyone knew there were problems? Everyone knew there were safety issues?
Bobbie Pauley: Absolutely. We all knew.
Anderson Cooper: Was there enough air in the mine?
Bobbie Pauley: Our section never had air.
Ventilation is critical to mine safety because fresh air carries explosive coal dust and methane out of the area where miners work. Without adequate ventilation and proper clean up, coal dust accumulates, and is not only highly flammable, it can cause black lung disease, which most of the miners killed in the explosion were later found to have.
Stanley Stewart: A lot of times we wouldn't have any ventilation at all. You couldn't see your hand in front of your face.
Anderson Cooper: Really? You couldn't see your hand in front of your face?
Stanley Stewart: Could not see your hand in front of your face.
Anderson Cooper: And that's because there's not air - fresh air moving through?
Stanley Stewart: Right, right.
Anderson Cooper: It's all dust?
Stanley Stewart: All dust.
As part of their case, prosecutors showed jurors the pumps miners were supposed to wear to measure their intake of coal dust, but at Upper Big Branch, Bobbie Pauley says they were routinely instructed by their bosses to cheat on the test, by hanging the pumps in the fresh air.
Bobbie Pauley: So your measurements when they were tested came in compliant with the law.
Federal mine inspectors visited Upper Big Branch almost daily but prosecutors say the mine had an illegal advance warning system in place. Security guards at the entrance would relay messages to miners underground alerting them an inspector was coming.
Anderson Cooper: They would use code words?
Stanley Stewart: Yeah, bad weather.
Anderson Cooper: They would say it's bad weather?
Stanley Stewart: Uh-huh. Which means we'll let you know if he's coming your way or going some other way.
Anderson Cooper: So you would get word from up above that "OK, an inspector's coming," they would use code words, and then you would basically clean up your area to make it look right?
Stanley Stewart: Uh-huh, yeah.
Upper Big Branch was a non-union mine. Inspectors were the only people miners could turn to for help. But they say, word was out, they shouldn't be seen talking to inspectors.
Anderson Cooper: Was there fear about speaking up?
Bobbie Pauley: If you wanted a job you kept your mouth shut. Me, like a lot of other miners, mining is about the only industry - it's the biggest industry in the state of West Virginia. You have children, you want them to have. You want to provide for them. I was a single mom, you know?
Anderson Cooper: You needed that job?
Bobbie Pauley: I did the best I could (crying). We did the best we could for our families. The guys did as well.
Steve Ruby: Some of the stories that they have to tell are horrifying. Being forced to work without enough fresh air, being forced to work in water up to their necks, miles underground. Being forced to work in areas of the where the roof and the walls of the mine were falling in around them.
Prosecutors say Blankenship was aware of all these safety problems because he was a micromanager who had oversight over every aspect of Massey mines, personally approving every hire, hourly raise, and capital expenditure.
Steve Ruby: He wanted everybody in that company to know he was in charge.
Booth Goodwin: Do it Don's way. "I expect you to do exactly what I tell you to do, when I tell you to do it."
Anderson Cooper: That was his message to his managers?
Booth Goodwin: Absolutely, time and again.
Steve Ruby: And that's on tape.
Don Blankenship on tape: This game is about money.
That message was repeatedly emphasized by Don Blankenship in phone conversations with mine managers he secretly recorded on these machines he installed in his office.
Don Blankenship on tape: I want you to take a deep breath and I want you to listen carefully. You ready?
Blanchard: Yes, sir.
Don Blankenship on tape: Being a group president and or someday being a VP at Massey or president of Massey requires that you be focused on dollars.
He sent terse handwritten notes and memos to managers criticizing them for high costs and low coal production..."you have a kid to feed" he wrote, "do your job"..."pitiful." "I could kruschev you"...and..."in my opinion children could run these mines better than you all do."
Anderson Cooper: The bosses were under pressure?
Stanley Stewart: They were under tremendous pressure.
Anderson Cooper: To keep mining, keep getting coal?
Stanley Stewart: Keep mining right.
Stanley Stewart: And they carried out his orders to the T. They treated the people under them as he treated them. I mean, he talked to them like they were dogs, they in turn talked to the superintendents or the section foremen, whatever, like they were dogs and kept that pressure applied to force these people to do his will.
Blankenship's attorneys called no witnesses at trial and pointed to safety initiatives their client put in place at Upper Big Branch.
Steve Ruby: Miner after miner after miner who worked at Upper Big Branch took the stand and said that the so-called safety initiatives were a joke. That the safety program stops at the entrance to the mine. And once you're underground your job is to run coal.
After two weeks of deliberations, a federal jury came to a landmark decision, finding Don Blankenship guilty of conspiring to willfully violate mine safety laws.
Attorney Bill Taylor outside courthouse: There was never enough evidence to justify convicting Mr. Blankenship.
But they didn't find him guilty of conspiring to defraud the Mine Safety and Health Administration or of lying to investors and regulators about safety violations, felony counts which could have sent Blankenship to prison for 30 years.
Under the law, jurors aren't allowed to know whether the counts they're considering are misdemeanors or felonies. And jurors told us, they were unaware the count they convicted him of was only a misdemeanor, which carries a maximum sentence of a year in prison.
Pam: I actually thought they were all felony charges.
Anderson Cooper: When you realized -- when you heard "OK, maybe he'll serve a year in prison," what was your gut?
Pam: I was surprised
Anderson Cooper: You were surprised Pam? In what way? Surprised it was so low?
Kevin: None of us actually knew. In terms of what the time was for the charges. I was- I was pretty pissed.
Family members of the dead miners, who attended the trial every day, were also disappointed.
Anderson Cooper: Do you think - was justice done in this verdict?
Sherry: No, no. There was no justice.
Judy Peterson lost her brother, miner Dean Jones.
Judy Peterson: As a result of the explosion, 29 people are gone. And that's a misdemeanor. That's a perversion of justice.
Steve Ruby: Do we think that a one-year sentence for what Don Blankenship has been convicted of is enough? No. We don't. But it's at least right now what the law gives us to work with.
Don Blankenship and his attorneys issued a statement to 60 Minutes denying that he was involved in any conspiracy. They claim the explosion was caused and fueled by a sudden and unexpected surge of natural gas, though three state and federal investigations found the deaths of the 29 miners were preventable, and the result of a failure of basic mine safety standards.
Anderson Cooper: Don Blankenship has said this was just an Act of God. That these kinds of things happen in coal mining.
Stanley Stewart: Well, you know, Don Blankenship, I'd like to take those words and stuff them right back down his throat because that was not an Act of God. That was man-made 100 percent.
Stanley Stewart: These men, you know, they weren't just 29 people that got killed. They were a lot of good men.
Anderson Cooper: And they deserved better than what they got?
Stanley Stewart: They deserved much better than they got.
Don Blankenship will be sentenced in April. Prosecutors say they will ask for the maximum one-year prison sentence and a fine in the tens of millions of dollars.