Six years after an explosion at Massey Energy's Upper Big Branch mine in West Virginia claimed the lives of 29 coal miners in the worst disaster of its kind since 1970, a court has rendered a sentence on Massey's former CEO, Don Blankenship -- who was convicted of "conspiring to violate federal mine safety standards." That sentence? One year in jail -- the maximum -- one year of supervised probation, and a $250,000 fine. All in all, it's a gross injustice, and on this week's edition of "So That Happened," we tally up the many outrages.

Chief among them, however, is the fact that now that Blankenship has gotten off with a slap on the wrist for fostering a corporate culture that imperiled the men he sent underground, prosecutors missed an opportunity to send a message to other mining company CEOs that the knives are out for similar malefactors. That $250,000 fine, while reportedly "well above what federal sentencing guidelines suggested ," is a pittance to a man like Blankenship, who "was paid a cool $18 million in 2009 -- his last year as CEO of Massey Energy before the explosion."

Assistant U.S. Attorney Steven R. Ruby argued that if Blankenship had received anything less than this single year in jail, it would have "signal[led] that committing mine safety crimes might be a good gamble for a CEO.

I have bad news for Mr. Ruby: Committing mine safety crimes is quite clearly still a good gamble for a mining company CEO, and you should expect mining company CEOs to continue making this gamble.