Tunnels at US-Mexico Border Show Smugglers' Deep Determination

Drug traffickers seeking to tap into the lucrative U.S. market have developed all kinds of secretive routes to smuggle their illicit products, including digging extensive and sophisticated tunnels under the U.S.-Mexican border. At the U.S. border with Mexico, VOA's Arturo Martínez toured a clandestine tunnel and learned just how difficult it is to stop the flow of illegal drugs.