US coal mining deaths surge in 2017 after hitting record low

http://www.pennenergy.com/articles/pennenergy/2018/01/coal-news-us-coal-mining-deaths-surge-in-2017-after-hitting-record-low.html?cmpid=enl_pennenergy_pennenergy_research_2018-01-04&pwhid=1e90004a8e081f3272fb5f8e0e9a20316c85258cc50faf993491663afd10a38f41b62c13180d825ec81f1c72848099c33ec83965e1b8e8ff4a01aa5c32296aec&eid=288118515&bid=1962887