An investigator combs through a drug tunnel found in a wherehouse on November 30, 2011 in Otay Mesa, California. The tunnel, which led from the United States to a small business building in Tijuana, was the most sophisticated tunnel ever found in California and included an elevator, wood flooring an lighting. (Photo by Sandy huffaker/Getty Images)
Mexico's smuggling tunnels
A look at various smuggling tunnels across the U.S.-Mexico border.