A tunnel that has been used for a year is used to smuggle migrants, weapons and cash across the U.S.-Mexico border.

Border Patrol uncovers a cross-border tunnel from Mexico to El Paso, equipped with lighting, ventilation, and wood supports, used for smuggling.

Workers have begun using concrete to close a narco tunnel that officials believe was build within the past year. The tunnel investigation continues.

Several federal agents have reportedly found a sophisticated "narco tunnel" in El Paso, Texas that has reportedly allowed cartel members to smuggle drugs and even humans into the U.S. undetected by border officers.