Suspected drug-smuggling tunnel found in Tijuana is so long authorities don't have enough oxygen to reach other end

The suspected drug-smuggling tunnel found last week in Tijuana, in northern Mexico, is so long that authorities haven't been able to find the exit point without oxygen tanks. Baja California's Secretary of Public Safety, Leopoldo Tizoc Aguilar Durán, said his team is in the process of getting the tanks to finish the investigation.

Aguilar did confirm that the tunnel is connected to another one found two years ago that does run into U.S. territory. American authorities have been notified of the finding and are looking for an exit point in the country, he said.

Previous tunnels found in the area could provide hints about the nature of this latest discovery. One found two years ago (although unclear if it's the one Aguilar was referring to) had the length of six football fields and featured rail and ventilation systems, electricity and reinforced walls. Concretely, it was a third of a mile long, four feet in diameter and about six stories deep.

It started in Tijuana and its exit point was an warehouse in an industrial area near San Diego's Otay Mesa border crossing. Six people found there, all southern California residents, were charged with conspiring to distribute cocaine.

A more recent finding in 2023, also in Tijuana, was 30 meters deep. However, since it was 20 meters long when found authorities couldn't conclude whether it sought to run all the way to the U.S. or connect with another one as part of a network.

Authorities have found close to 20 tunnels on California's border with Mexico since 2006, according to CBS News. Last week's was the first such find this year. Neither American nor Mexican officials have confirmed the tunnel was used to smuggle drugs. In accordance with federal law, U.S. authorities must fill the local side with concrete after tunnels of the kind are discovered.