San Diego Union-Tribune – Sinaloa cartel leader Joaquin “El Chapo” Guzman’s prison escape last weekend required both planning and support from the inside, experts said. It also took something else: the ability to build an underground tunnel. The Sinaloa cartel for years has been honing its tunnel-building skills on the U.S.-Mexico border, where it has been linked to numerous passageways used to smuggle drugs.
