Federal agents found a secret big tunnel that runs from Tijuana, Mexico, to Otay Mesa, California. It's apparently 1,200 yards long and runs between two warehouses on either side of the border. Two tons of pot were discovered inside. From CNN:
Made of concrete, the passageway had lighting, electricity, ventilation and a pump to remove water, said Lauren Mack, a spokeswoman for Immigration and Customs Enforcement...Link
Mack said human intelligence led to the discovery of the underground structure. Agents then used ground-penetrating radar technology from the military to find anomalies in the soil, she said.