Darkness Underground News Today

In the past month alone, three new tunnels have been discovered in one border town. tonight for the first time, we will take you inside for a look at what is really hang underground. ed laven tara is "o-- lavandara "out front." >> reporter: take a look in mexico where world security is not in the darkness underground. in the drainage system under the city of nogales, mexico, often used by drug smugglers to get people and drug into the united states. local police guide us through the rivers of ra...