The tunnel featured an extensive rail cart system, forced air ventilation, high voltage electrical cables and panels, an elevator at the tunnel entrance and a drainage system. The next longest tunnel in the US was discovered in San Diego in 2014. The newly discovered tunnel is about 1.68m tall and 0.61m wide, officials said. US authorities said they are confident that the tunnel exited in San Diego at one time, based on its trajectory. An incomplete offshoot of the tunnel that extended 1,090m suggested to authorities that smugglers had plugged an initial exit point and were building another.

Source: Taipei Times January 30, 2020 16:03 UTC