On December 3, 2015, a jury empaneled in the United States District Court for the Southern District of West Virginia convicted Donald L. Blankenship of conspiracy to violate federal safety standards, and although he will serve a maximum sentence of one year in prison, his conviction sends a message to leaders in the mining industry that safety should be its primary focus. Blankenship, as leader of Massey Energy Company, drew intense scrutiny and criticism after 29 mine workers were killed in an explosion at the Upper Big Branch mine in 2010, the worst U.S. mine disaster in forty years.

While this tragedy brought to light ongoing safety concerns in the mining industry, Blankenship’s trial serves as a cautionary tale to a much broader audience. Blankenship was charged with and convicted of conspiracy based on evidence that Blankenship set an example to employees that Massey valued profits over safety.

For example, on October 19, 2005, Blankenship circulated a memorandum to all Deep Mine Superintendents, asking them to ignore directions to “do anything other than run coal.” He used building overcasts and doing construction jobs as examples. Aside from the obvious implication that “anything” includes taking appropriate safety precautions, it is important to note that an overcast is an enclosed airway permitting one air current to pass over another without interruption, and construction jobs include building cribs or other safety structures. Blankenship later circulated another memorandum clarifying the first, but, as the first made its way into his trial nine years later, it is clear he was not able to unring the bell. Even in isolation, this memo was damaging to his defense, but it was especially so in light of other internal memoranda and recordings that revealed a Company that seemingly put its employees in the way of tremendous harm.

History has shown that the ease of drafting a quick email or memo can lure even the most powerful and sophisticated executives into a situation where they are potentially drafting the exhibits for their trial. Some best practices in internal communication are, first of all and easiest, to step back and read it again. In fact, when it comes to important issues like workplace safety, read it like a federal prosecutor would. Second of all, be especially cautious in areas where your company (or your company’s industry) has received scrutiny in the past. It’s great to learn from your mistakes – it is better to learn from others’ mistakes. And finally, when in doubt, do not send it. You can send it later, but, retraction or not, you can never take it back.