YUMA, AZ (CBS5/AP) -
Authorities said they have discovered a major cross-border drug tunnel that is linked to a commercial building in San Luis.
The Drug Enforcement Administration announced the details of a 240-yard passageway that was equipped with lighting and ventilation Thursday morning. U.S. Justice Department officials said the sophisticated tunnel, which was reinforced with 4x6 beams, was used to transport drugs from an ice plant in San Luis Rio Colorado, Sonora, Mexico, to the commercial building on the Arizona side.
"The tunnel cost about $1 million to $1.5 million to complete it," DEA agent in charge Doug Coleman said.
"I would suspect that based on how far down it was that they had engineers that were cooperating with them," he continued.
The tunnel was reportedly more than five stories underground and was one block from a border checkpoint.
Authorities said the investigation also includes three arrests and drug seizures.
As U.S. authorities have tightened land crossings, tunnels have become a popular way for Mexico's cartels to smuggle drugs and people into the U.S.
Officials said the tunnel was being used to transport hard drugs across the border, like heroine. They estimate it took about one year to build but was not in operation for very long.
DEA agents are coordinating the ongoing investigation into the tunnel. Law enforcement officials from Mexico are also aiding in the investigation
DEA officials said the San Luis passageway is the only known completed and fully operational smuggling tunnel ever uncovered in the Yuma, AZ, area. In the past 10 years, 89 cross-border tunnels have been discovered in Arizona and 50 in California.
Copyright 2012 CBS 5 (Meredith Corporation). All rights reserved. The Associated Press contributed to this report.
