Sophisticated 'Super' Drug Tunnel Between California and Mexico Discovered

— -- A sophisticated, super tunnel was discovered by federal officials Wednesday night near San Diego, leading to the arrest of 22 people and confiscation of 12 tons of marijuana estimated at $6 million.

Isaias Enriquez-Acosta, 53, and Isidro Silva-Acosta, 27, were charged Thursday with unlawful conspiracy to import a controlled substance and conspiracy to use border tunnels and passages.

Agents found a hole in the floor near a warehouse in Otay Mesa -— a city south of San Diego -- that led to a shaft descending almost 32 feet down in the ground. The shaft connected to an underground passageway, which included lighting, ventilation and a rail system, leading to the U.S.-Mexico border.

“We see a super tunnel open for business once every year or so,” U.S. Attorney Laura Duffy told ABC News today. “Just when they think they’re ready to move, we put it out of business.”

The Tunnel Task Force conducted a six-month investigation that revealed the 2,600-foot long tunnel, to be one the largest uncovered along the southern border in recent years.

Since 2010, federal authorities have found more than 75 smuggling tunnels, mostly in California and Arizona.

“The success of this investigation is yet another example of our commitment to secure the border while combating the increasingly dangerous underground smuggling activity,” said Dave Shaw, special agent in charge for ICE Homeland Security Investigations in San Diego.