Drug smuggling tunnel with rail system uncovered on US-Mexico border | US news

US authorities have discovered an underground smuggling tunnel on the California-Mexico border that runs the length of six football fields and contains reinforced walls, electricity, ventilation and a rail system.

Investigators discovered the tunnel, which led to a warehouse in an industrial area on US soil, last week. The tunnel is located about half a mile (0.8km) from the Otay Mesa border crossing between Tijuana and San Diego, in an area where more than a dozen others have been discovered in the past two decades.

After staking out a home that had recently been used as drug stash house, agents began making traffic stops of vehicles near the warehouse, turning up boxes full of cocaine, according to a federal criminal complaint filed in US district court in San Diego.

They raided the properties – finding no other drugs at the warehouse, but a tunnel opening carved into the cement floor, federal prosecutors said. The tunnel ran one-third of a mile to Tijuana. It was 4ft (1.2 meters) in diameter and about six stories deep.

Agents seized 1,762lb (799kg) of cocaine, 165lb (75kg) of meth and 3.5lb (1.6kg) of heroin from the vehicles and the residence, and they arrested six people on federal drug conspiracy charges.

The cross-border tunnel was built in one of the most fortified stretches of the border, illustrating the limitations of Donald Trump’s border wall. While considered effective against small, crudely built tunnels called “gopher holes”, walls are no match for more sophisticated passages that run deeper underground.

Authorities have found about 15 sophisticated tunnels on California’s border with Mexico since 2006.

Many tunnels, including the one announced Monday, are in San Diego’s Otay Mesa industrial area, where clay-like soil is conducive to digging and warehouses provide cover.

The cross-border passages date back to the early 1990s and have been used primarily to smuggle multi-ton loads of marijuana. The US Drug Enforcement Administration said in 2020 that they were generally found in California and Arizona and associated with Mexico’s Sinaloa cartel.

By federal law, US authorities must fill the US side of tunnels with concrete after they are discovered.