"The average lifespan [of a tunnel] could be a perpetual ... unless you have specific information from a human source, or there's unusual activity detected that would warrant a closer look, you're not going to fine those tunnels," Vigil told Business Insider. Tunnels are "a smuggling method that will probably continue and probably increase in the future, especially with the increased border patrols and the surveillance that is taking place along the border."
A reporter uses a torch to light marijuana packages inside a truck parked at a warehouse where the Mexican army located a cross-border tunnel in Tijuana, July 12, 2012. The army located a tunnel measuring 383 yards running to California from Mexico and seized some 50 tons of marijuana, local media reported. The tunnel was still under construction but had ventilation and lighting.