NEW YORK — Ventilation tubes and electricity cables run along the rough-hewn walls. Rudimentary rails stretch along the ground. The dank, waterlogged conditions belie the desert conditions at the surface, some 70 feet above.
Pictures and video of the remarkable smuggling tunnel, the longest ever found at the Mexico-US border, were released by US authorities Wednesday. The shaft stretched some 4,309 feet, or just over eight-tenths of a mile, from Tijuana, Mexico, to the outskirts of San Diego.
“The sophistication and length of this particular tunnel demonstrates the time-consuming efforts transnational criminal organizations will undertake to facilitate cross-border smuggling,” Cardell T. Morant, acting special agent in charge of Homeland Security Investigations in San Diego, said in a statement from Customs and Border Protection.
Before the latest discovery, the longest smuggling tunnel across the US-Mexico border was an excavation found in 2014, also in San Diego, authorities said. That tunnel was 2,966 feet long.
For all the talk about a wall between the United States and Mexico, the proliferation of such subterranean passageways demonstrates that the problem with border security is as much below ground as above.
Cross-border tunnels have long been used by cartels to move drugs and people into the United States, but even so, the sophistication of the recent find stood out, the US border agency said.
Images and footage taken inside the tunnel showed a claustrophobic channel hacked through rock, measuring just 2 feet across and about 5½ feet high. Officials said the shaft was equipped with a rail system and ventilation, high-voltage electrical cables, a drainage system, and an elevator at the opening in Tijuana.
The video shows wires dangling from the walls, ventilation equipment and detritus including discarded clothing, and what looked like the remains of wooden storage shelves. Water sloshes around the floor of the chambers.
The exit on the US side was hidden by hundreds of sandbags, authorities said. An offshoot of the main tunnel was also discovered, they added, running 3,529 feet into US territory but with no opening to the surface.
US authorities said that no arrests had been made in relation to the discovery and that no drugs had been found inside the tunnel. The border area has been a stronghold of the Sinaloa Cartel of Mexico, whose leader, Joaquín Guzmán Loera, known as El Chapo, was sentenced to life in prison in July.
In 2015, Guzmán staged a stunning escape from prison in Mexico, vanishing from his cell in full view of a video camera through a tunnel that was more than 600 feet longer than the one announced Wednesday. That tunnel was one of the longest ever built by the cartel, though it did not cross the border.
Guards later discovered a small hole in the floor of his shower that led to a nearly mile-long tunnel 30 feet underground. The shaft was equipped with lighting, ventilation, and a motorcycle on rails. Some engineers estimated it had taken more than a year and at least $1 million to build.
The authorities have been trying for decades to find and cut off cross-border tunnels, many of which include lighting and ventilation systems and have been used by the Sinaloa cartel to move drugs quickly.
In 2018, a cross-border tunnel was discovered in Jacumba, about 55 miles east of San Diego, with a similar rail system and solar-powered lighting.
After the discovery of the latest tunnel, the US border agency said that Mexican authorities had identified the opening on the southern side and that American investigators had then mapped the entire construction.
On the US side, the shaft emerged in the industrial neighborhood of Otay Mesa, on the southern outskirts of San Diego, an area that has been a favorite spot for tunnels because of its easy-to-dig soil and the presence of many warehouses that provide cover. Many tunnels end in these warehouses, making them difficult to detect.
The length of the tunnel, equivalent to 14 football fields, prompted surprise.
“We never really thought they had the moxie to go that far,” a Border Patrol operations supervisor, Lance LeNoir, told The Associated Press. “They continue to surprise me.”