The longest smuggling tunnel ever found along the US-Mexico border has been discovered by border patrol officials.
Stretching more than three-quarters of a mile, the tunnel ran from an industrial site in Tijuana, Mexico, into the San Diego area.
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.
While there were no arrests, no drugs found at the site and no confirmed exit point in the US, the length - more than 14 football fields - stunned authorities.
"This one blows past (the second-longest)," said Lance LeNoir, a US Border Patrol operations supervisor.
"We never really thought they had the moxie (confidence) to go that far. They continue to surprise me."
The tunnel exposes the limitations of President Donald Trump's border wall, which stretches several feet underground in the area and is considered effective against small, crudely built tunnels often called "gopher holes".
The tunnel was found about 70 feet underground, well below the wall.
Following the tunnel's discovery in August, Mexican law enforcement identified the entrance and US investigators mapped the tunnel, which extends a total of 4,309 feet.
The next longest tunnel in the US, discovered in San Diego in 2014, was 2,966 feet long.
The newly discovered tunnel is about five-and-a-half feet tall, two feet wide, and runs at an average depth of 70 feet below the surface, officials said.
