Seven of the largest tunnels discovered under the U.S.-Mexico border in recent years have yet to be filled in, authorities said, raising concerns because smugglers have tried to reuse such passages before.
Among the unfilled tunnels, created to ferry people and drugs, is the longest one yet found—extending nearly half a mile from San Diego to Tijuana. Nearby, another sophisticated passageway once known as the Taj Mahal of tunnels has been sitting unfilled for 13 years, authorities say.
Though concrete plugs usually close off the tunnels where they cross under the border and at main entrance and exit points, the areas in between remain largely intact. Filling the seven tunnels would cost about $2.7 million, according to U.S. Customs and Border Protection officials. Accessing tunnels that run under private property is also a problem, as is a lack of coordination with Mexican authorities.
Mexican authorities have told their U.S. counterparts that they’ve filled their end of the tunnels. But U.S. officials express doubt, citing the high costs and examples of tunnels being compromised. The Mexican attorney general’s office, which handles organized crime, did not respond to numerous requests for interviews.
In recent years nearly 50 tunnels have been discovered running under the border from San Diego to Arizona. Most are small, crudely constructed passages—called gopher holes—that are easily destroyed.
But filling the larger, more elaborate tunnels requires enormous amounts of material and expertise, especially because some were probably designed by mining engineers.
In Nogales, Ariz., traffickers have used one tunnel three times over a four-year span. Tijuana smugglers were suspected of reusing a tunnel in 2004, one year after its discovery inside a house in Mexico. U.S. authorities have had to reinspect several other tunnels in response to suspicious activity or tips.
Authorities cite this streamlining as progress. But Customs and Border Protection has not filled any tunnels, and has capped only two since assuming control. Michael Friel, an agency spokesman, said the agency is trying to find money in its budget to complete the work. The 2007 budget for Customs and Border Protection is $7.8 billion.
Critics say the existence of so many unfilled tunnels poses a needless—and inexcusable—national security risk.
Among the unfilled passages:
* The so-called Grande Tunnel connecting warehouses in San Diego and Tijuana. Nearly half a mile long, the tunnel was discovered in January 2006 and attracted global media attention as well as groups of local and national politicians, who were given tours of its cave-like depths. The tunnel prompted Feinstein to propose legislation outlawing the construction of tunnels under the border.
* The 1,400-foot tunnel called the “Taj Mahal” because of its lighting system and reinforced concrete walls. The tunnel was discovered in 1993. Five years later, authorities suspected the passage had been reentered after 33 illegal immigrants were found covered in mud near the opening. A metal lid over the tunnel opening had been cut. Border Patrol agents say they never determined for sure if the passage was reused.
* Two long tunnels leading from Mexicali, Mexico, to a quiet residential area in Calexico, Calif. One of them, discovered in 2005, was equipped with a ventilation system, phone line and video surveillance equipment.
It isn’t cost alone that can keep tunnels unfilled. Owners of private property also can slow the process. In 2002, after a tunnel was discovered running under part of his property in eastern San Diego County, David Field, a San Diego building inspector, feuded with the DEA over how to fill the quarter-mile-long passage. The DEA wanted to use a concrete-soil mix. Field, for environmental reasons, said he wanted the portion under his land filled only with dirt.
The tunnel featured a battery-operated cart on rails and was used to ferry what may have been tons of drugs over a 10-year period, according to authorities.
In 2002, the DEA sent Field a letter saying that drug traffickers would probably reuse the tunnel if it wasn’t completely closed off and threatened to seize Field’s property if the tunnel was compromised. Field said the letter surprised him because he knew the agency had never filled the Taj Mahal tunnel found in 1993.
Digging a new route
This month, authorities returned to the house again. This time, two men were digging a new route, starting inside the home, Cano said. They had progressed only 15 feet, Cano said, but may have intended to link up again with one of the existing tunnels under the property.
None of the passages have been filled, Cano said, although he believes portions may have collapsed because of heavy rains. Even if the tunnels were filled, he said, the problem might not go away.
That’s because smugglers have used the concrete fill to make support walls and ceilings for new tunnels, he said. The filled-in passages also serve as markers, guiding crews to new areas where they want to go below ground.
Mexican authorities have occasionally permitted their U.S. counterparts to inspect tunnels for suspicious activity, including one time when a corpse was discovered on the Mexican side. But it’s not routine.
Corruption in Mexican border agencies complicates matters. Last year, two Mexican customs officers were arrested on suspicion of being involved in the construction of a tunnel near the San Ysidro Port of Entry.
“If they’re not filled in, [smugglers] just branch out at one end or another.”