Nogales sheriff Tony Estrada says this was one of the most sophisticated operations he's ever seen.
The tunnel connects to the storm drain that flows between Nogales, Ariz., and Nogales, Sonora in Mexico. The smugglers would pass through the storm drains and then enter their homemade tunnel system. Set up with electric lights and ventilation, U.S. customs officials say it would have been a major pipeline
"Tunnels will make it easier to bring in large loads," says U.S. customs official Raymond Kelly. "Now one tunnel is only 2 ft. by 2 ft. by 2 ft., but you can put a rail system through there and obviously you can take small packages and put large numbers of small packages through the tunnel."
Behind the house in an apartment was another trap door to a second tunnel about two miles long and too dangerous to explore. Investigators stopped at a steel door found buried deep beneath a Catholic school.
Nogales police say the level of sophistication is a sign that a major Mexican drug cartel is involved. Federal authorities say the competition between the cartels and lesser rival drug gangs is heating up.
"I think it just shows the intensity and extent to which they'll go to get drugs into America," Kelly says.
However, this time police believe they were able to close the door on this operation before it could really get off the ground.
Reported By Sandra Hughes