A U.S. Drug Enforcement Agent (DEA) aims a flashlight down a 55 foot deep drug smuggling tunnel that runs almost 240 yards under the U.S.-Mexico Border cut through a floor of a small industrial unit south of Yuma, Arizona in the town of San Luis. It is estimated that the tunnel built by a Mexican drug cartel cost up to 1-million dollars and took one year to build..(Credit Image: © Louie Palu/ZUMA Press)