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. >> pauley: so your measurements when they were tested came in compliant with the law. >> cooper: federal mine inspectors visited upper big branch almost daily but illegal advance warning system in place. security guards at the entrance would relay messages to miners underground alerting them an inspector was coming. >> cooper: they would use code words? >> stewart: yeah, bad weather. >> cooper: they would say it's bad weather? >> stewart: uh-huh. which means, we'll let you know if he's coming your way or going some other way.

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. >> pauley: so your measurements compliant with the law. >> cooper: federal mine inspectors visited upper big branch almost daily but illegal advance warning system in place. security guards at the entrance would relay messages to miners underground alerting them an inspector was coming. >> cooper: they would use code words? >> cooper: they would say it's bad weather? >> stewart: uh-huh. which means, we'll let you know if he's coming your way or going some other way. >> 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? >> stewart: uh huh, yeah. >> cooper: 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. was there fear about spea

the coal on the belt. >> cooper: bobbie pauley was the only female miner at upper big branch. she wasn't working the day ofce e boone payne was. he died in the blast. bobbie says she and boonee mine was an accident waiting to happen. everyone knew there were problems? everyone knew there were safety issues? >> pauley:w. >> cooper: was there enough air in the mine? >> pauley: our section never had air. >> cooper: ventilation iscause fresh air carries explosive coal dust and methane out of the area where miners work.on and proper clean up, coal dust accumulates, and is not only highly flammable, it can causeich most of the miners killed in the explosion were later found to have. >> stewart: a lot of times we wouldn't have any ventilation at all. in front of your face. >> cooper: really? you couldn't see your hand in front of your face? >> stewart: could not see your hand in front of your face. >> cooper: and that's because >> stewart: right, right. >> cooper: it's all dust? >> stewart: all dust. >> ruby: this is what's called a dust pump. >> cooper: as part of theired jurors the

. >> bobbie pauley: erythingngaspp prode,e,e,duce, produce. itidn'make a differencof thngerer ititn'makeny difrencif had tshuts. itasllbout toae be>> cr: bbiulashehe onlyalmir u big brch. she wasnsn workingheayf boone payne e s. he died in the b bst.. boboie says shehand d one worried every day thmine was an acaident waitg totoappen. everyone knew there were problele? everyone knew there were safety ises? >> pauley: absbsutely. we all knew. cooper: was there enough air in the mine? >> pauley: o o section never had air. >> cooper: v vtilalaon is critical to o ne safety because fresh air carrieexplosive coal dust and methane out of the area where minersrsork. withouadequate ventilati and propor clele up, coal dust culatete ands not onlyly ly fmmleit cau ack lung d dse, whicst tkied in e pliowereaterndo ha.>> stetertt timeseul't have anannt couldn'tound frt ofofour >>oor: ry?yocouldl't see yha in frt ofour fafa? >> stewa: could not your nd in front of your face. >> cooper: and thas becae there's noair fresh air ving through? >> stewart: right, ri