U.S. Border Patrol agents have uncovered a nearly 3,000-foot-long underground tunnel used for narcotics smuggling beneath the U.S.-Mexico border, linking Tijuana and San Diego. The tunnel was found in early April while it was still under construction, authorities said.

According to Fox 11 Los Angeles, the tunnel stretched approximately 2,918 feet, reached a depth of 50 feet, and featured lighting, ventilation, electrical wiring, and a rail system to transport drugs. It measured 42 inches high and 28 inches wide.

The projected exit point was near or inside a commercial warehouse space in San Diego, just under the Otay Mesa Port of Entry. Agents found the tunnel's entrance inside a house in Nueva Tijuana, where it had been recently concealed with fresh tile.

Authorities say thousands of gallons of concrete will be poured into the tunnel to permanently seal it and prevent its use by Foreign Terrorist Organizations.

“Disruption of narcotics smuggling tunnels is critical to protecting American lives,” said Jeffrey D. Stalnaker, acting chief patrol agent of the San Diego Sector.

Since 1993, more than 95 drug tunnels have been discovered and decommissioned in the San Diego area alone.