priscilla petra believes the equipment must have been broken. >> i just know that if that had worked,would have walked out of there. they weren't that far underground. they were under there, i'm not sure exactly how far but they could have walked out of there had they had that-- the oxygen. >> i feel like these men are a dime a dozen in the coal operators' eyes. it's all-- it's all in the product. "we want the money. get the coal out, get the coal out, get the coal out. >> why do you think the families of the miners who died are blaming the mine operators to such an extent? why do you think they're so convinced that the mine operators were at fault here? >> it's always that way. it's never been different. if i had a family member who died in the mines, i might feel the same way. that's an emotional response and it's-- you want somebody to blame. >> are you saying that the reality is that the mine operators are not responsible for the fatalities? >> yes. i'll say that. >> kent hendrickson says that miners are often responsible for accidents, and some of them, he points out, go to work