@wallstreetjournal: Some 700 yards deep in Colombia’s richest gold mine, private security guards crouch behind sandbags, trapped in a failing battle with a drug-trafficking gang that has commandeered 30 miles of tunnels worth hundreds of millions of dollars. Mine owner Zijin Mining Group, a Chinese state-controlled company, estimated that last year it lost more than 3.2 tons of gold, worth around $200 million and equal to 38% of the mine’s total production. 📷: Nicolas Enriquez for WSJ, Mauricio Duenas Castaneda/Shutterstock Reporter: Juan Forero Host/Producer: @jacob.ohara #colombia #gold #crime #wsj