U.S. authorities announced on Wednesday that they discovered the longest smuggling tunnel ever found on the southwest border, extending from Mexico into the San Diego area. “While subterranean tunnels are not a new occurrence along the California-Mexico border, the sophistication and length of this particular tunnel demonstrates the time-consuming efforts transnational criminal organizations will undertake to facilitate cross-border smuggling,” said Cardell T. Morant, the special agent leading Homeland Security investigations in San Diego. The elaborate tunnel features an extensive rail/cart system, ventilation, high-voltage electrical cables and panels, an elevator, and a drainage system, the agency said. The tunnel originates in Tijuana and stretches 4,309 feet, according to the U.S. Customs and Border Protection. Mexican law enforcement identified the tunnel entrance in August 2019, which kicked off a major effort by members of the San Diego Tunnel Task Force to map the tunnel from Mexico, the agency said. The second longest tunnel in the U.S., measured at 2,966 feet, was discovered in San Diego in 2014.