By U-T San Diego 5:57 p.m.Oct. 31, 2013

This is a list of tunnels found along the southwestern United States border since 1990 compiled from news reports, press releases and other unclassified sources. Since 1990, law enforcement officials have discovered more than 140 tunnels underneath the U.S. border.

Otay Mesa, Calif. October 30, 2013. San Diego Drug Tunnel Task Force members found a tunnel linking warehouses on both sides of the border.

Nogales, Mexico. June 25, 2013. A routine bi-national inspection of Nogales' main storm drain system revealed an incomplete 160-foot tunnel.

Nogales, Mexico. February 22, 2013. Mexican authorities arrested a man digging a tunnel west of the DeConcini port of entry.

Nogales, Ariz. February 13, 2013. Federal authorities shut down crude, hand-dug tunnel approximately 68-feet-long and seized more than 1,200 pounds of marijuana.

Mexicali, Mexico. January 5, 2013. Mexican authorities found a partially completed tunnel 33 feet underground that included ventilation and lighting systems.

Nogales, Mexico. December 27, 2012. Mexican authorities discovered an incomplete 360-foot-long tunnel equipped with electricity and ventilation.

San Luis, Ariz. July 2012. A tunnel equipped with electricity and a ventilation system was found linking an empty business in San Luis, Ariz., with an ice plant in Mexico.

Tijuana, Mexico. July 11-12, 2012. Two incomplete underground passageways were found under construction in Tijuana. The second extended about 1,150 feet near the border fence in Otay Mesa and held 50 tons of marijuana.

Nogales, Mexico. March 1, 2012. Federal agents discovered about 550 pounds of bundled marijuana inside a 110-foot drug smuggling tunnel.

Nogales, Mexico. Dec. 10, 2011. The Mexican army announced the discovery of a 50-yard long tunnel.

Otay Mesa, Calif. Nov. 29, 2011. U.S. authorities found a cross-border drug tunnel inside an Otay Mesa warehouse complete with a small elevator, ventilation and an electric rail system.

Nogales, Ariz. Nov. 21, 2011. Border Patrol agents discovered 430 pounds of marijuana in a tunnel that stretched 319 feet from Mexico into the United States, and had been chiseled through rock 20 feet underground.

Otay Mesa, Calif. Nov. 15, 2011. U.S. and Mexican officials recovered more than 20 tons of marijuana after discovering a cross-border drug tunnel that stretched from a warehouse just east of the Tijuana airport in Mexico, near the border fence, to a warehouse on Kerns Street in Otay Mesa.

Nogales, Ariz. Nov. 15, 2011. A tunnel being used to smuggle drugs under the border into the United States was discovered with an entrance concealed under the front porch of a home about a half-mile west of the DeConcini Port of Entry.

Otay Mesa, Calif. Nov. 2, 2011. Border Patrol agents arrested five people suspected of trying to enter the U.S. illegally who became stuck while crawling through a makeshift tunnel which branched off of an abandoned gas line near the Otay Mesa port of entry.

Nogales, Ariz. Sept. 1, 2011. Mexican federal police found a tunnel dug into a border storm drain that leads into the United States. An exit on the U.S. side was hidden by a cover piled over with dirt.

Calexico, Calif. Aug. 25, 2011. U.S. authorities discovered an incomplete pipeline-style smuggling tunnel beneath a vacant supermarket near California-Mexico border.

Douglas, Ariz. Aug. 24, 2011. Acting on a tip, officials discovered an incomplete tunnel in a house being built from the United States southward.

Nogales, Ariz. Aug. 16, 2011. Immigration and Customs Enforcement and Border Patrol agents found an active tunnel about 90-feet-long, shored up by two-by-fours and plywood, similar to a mining shaft.

Tijuana, Mexico. August 12, 2011. The Mexican army uncovered an incomplete drug tunnel with lights and ventilation stretching abou 110 yards into the United States.

Nogales, Ariz. May 25, 2011. A landlord discovered an incomplete cross-border tunnel at a rental house located near East Street and North Nelson Avenue in Nogales.

Nogales, Ariz. May 5, 2011. A 250-foot tunnel about three feet wide by five feet tall was cut through solid rock. It contained electricity, water pumps, and ventilation.

Nogales, Ariz. Jan. 9, 2011. Border Patrol agents found two tunnels under construction. The tunnels were approximately 2 feet wide by 3 feet tall; one tunnel extended about 10 feet into Arizona.

Nogales, Ariz. Dec. 14, 2010. Immigration agents discovered a 13-foot drug tunnel stretching from the Mexican border to a metered parking space. Vehicles with holes cut in the bottom would park in the space and take marijuana from people underground.

Otay Mesa, Calif. Nov. 25, 2010. Law enforcement agents arrested eight people and seized more than 20 tons of marijuana in connection with 2,200-foo cross-border tunnel equipped with lighting, ventilation, and a rail system for drugs to be carried on a small cart.

Otay Mesa, Calif. Nov. 2, 2010. U.S. federal agents discovered an 1,800-foot tunnel that was equipped with lighting, ventilation and a crude rail system.

Nogales, Ariz. Sept. 30, 2010. After seizing 665 pounds of marijuana Border Patrol agents discovered an illicit tunnel paralleling the drainage system.

Nogales, Ariz. Aug. 20, 2010. A passenger bus headed into Mexico caused a partial collapse in the road, revealing an unfinished tunnel under the southbound lane at the DeConcini Port of Entry.

El Paso, Texas. June 25, 2010. U.S. Border Patrol agents discovered a tunnel that stretched 130 feet under the Rio Grande from Mexico into the U.S., the first such tunnel in El Paso region.

San Ysidro, Calif. June 5, 2010. Mexican authorities announced that an incomplete smuggling tunnel was found east of the San Ysidro Port of Entry. The passageway is about 500 feet long, more than a yard wide and 2½ feet high.

Tijuana, Mexico. March 11, 2010. Mexican authorities found an incomplete smuggling tunnel leading from a warehouse southeast of the Otay Mesa border crossing. The 250-foot-long passageway, which was shored up with wood and had lighting, was about 4 feet tall, 2 feet wide and about 20 feet underground.

Tijuana, Mexico. Feb. 12, 2010. Images from a video surveillance camera led Mexican authorities to a suspected smuggling tunnel under construction in Tijuana inside a guarded federal customs facility at the Otay Mesa border crossing.

Nogales, Ariz. Dec. 23, 2009. Border Patrol agents investigating a sinkhole found a reinforced tunnel still under construction that measured 36 feet long and extended 25 feet into the United States.

Tijuana, Mexico. Dec. 2, 2009. Acting on a tip received by U.S. officials, Mexican authorities discovered a tunnel equipped with an elevator and lighting and electrical systems just west of the Otay Mesa Port of Entry. The tunnel, which did not yet have an opening on the U.S. side, was about 1,000 feet long and up to 100 feet deep in some areas.

Calexico, Calif. Nov. 12, 2009. An unfinished 20-foot shaft, measuring 6 feet by 6 feet, was found by Mexican soldiers.

Tijuana, Mexico. Nov. 7, 2009. Mexican soldiers detained six people at the site of an incomplete, 400-foot tunnel near the U.S. border fence west of A.L. Rodriguez International Airport.

Tijuana, Mexico. Oct. 27, 2009. The Mexican army discovered an incomplete tunnel, equipped with electricity and an air supply, just west of the Otay Mesa Port of Entry.

Nogales, Ariz. Oct. 22, 2009. Border Patrol agents found an unfinished 30-foot-long tunnel, located 150 yards east of the DeConcini Port of Entry.

San Ysidro, Calif. June 30, 2009. U.S. agents unearthed a cross-border tunnel that connected several drainage systems on both sides of the border, shored up with plywood and equipped with battery-powered lights. The U.S. exit to the tunnel covered by a sofa cushion on the grounds of the South Bay International Wastewater Treatment Plant. The entrance in Tijuana, located east of Smugglers' Gulch, was a manhole along Avenida Internacional.

Nogales, Ariz. June 10, 2009. Authorities found an incomplete 83-foot-long cross-border tunnel, which was constructed with side walls framed with 2x4 wooden studs and lined with plywood.

Nogales, Ariz. May 11, 2009. Border Patrol agents found a crude dirt tunnel about 50 feet north of the international border fence.

Otay Mesa, Calif. March 29, 2009. Border Patrol agents monitoring surveillance cameras spotted someone crawling out of a hole near the border fence about one mile west of the Otay Mesa port of entry. Agents discovered a crude tunnel, about 15 yards long, running under a nearby road. It opened near a drainage ditch.

Otay Mesa, Calif. Feb. 21, 2009. Border Patrol agents discovered a smuggling tunnel about 110 feet north of the border near Via de la Amistad, just east of the Otay Mesa border crossing that authorities suspect was built to connect a storm drain in the United States to an unused natural gas pipeline in Mexico. The tunnel was about 3 feet wide and 3 feet tall and reinforced with wooden beams.

Nogales, Mexico. Jan. 20, 2009. Mexican federal police announced the discovery of three suspected drug tunnels under construction in the city of Nogales near the Arizona border.

Nogales, Ariz. Dec. 29, 2008. U.S. Border Patrol agents found a crude tunnel, hidden with clumps of grass, during a routine patrol.

Nogales, Ariz. Dec. 13, 2008. Nogales police officers found a tunnel west of the DeConcini Port of Entry along International Street.

Nogales, Ariz. Dec. 12, 2008. Police officers patrolling near downtown Nogales found another tunnel east of the DeConcini Port of Entry, about eight feet north of the border.

Nogales, Ariz. Dec. 10, 2008. Border Patrol agents found a makeshift tunnel about one foot from the fence separating the United States from Mexico with an exit point in a flood culvert which runs under the border.

San Ysidro, Calif. Dec. 10, 2008. A short and incomplete cross-border tunnel was discovered when a bus tire sank into a roadway along the border fence. The tunnel, which extended about 10 feet into the United States, was about 15 feet underground and 3 feet in diameter.

Nogales, Ariz. Nov. 19, 2008. U.S. Border Patrol agents discovered two tunnels during routine sweeps of the Grand Avenue underground drainage tunnel.

Nogales, Ariz. Oct. 25, 2008. Border Patrol agents found a tunnel opening, covered by plywood and sandbags, about half a mile from the DeConcini Port of Entry and 175 feet north of the border.

Calexico, Calif. Sept. 1, 2008. Mexican agents arrested eight people working on a 434-foot passageway in the upper-middle-class neighborhood of Colonia Nueva in Mexicali. The tunnel had an elevator, lighting and ventilation and came to within 130 feet of U.S. territory.

Otay Mesa, Calif. April 2, 2008. A tip lead authorities to an unfinished tunnel about 2 feet in diameter that stretched 14 feet across the border.

Nogales, Ariz. Jan. 16, 2008. This tunnel consisted of three short tunnels connected to approximately 250 ft. of storm drain to create one continuous passage.

Nogales, Ariz. Dec. 18, 2007. A Nogales police officer discovered a stretched 135 feet from a wash in Mexico to the kitchen of a house in Arizona. More than 1,390 pounds of marijuana were found inside the home.

Nogales, Ariz. Dec. 11, 2007. Images from a surveillance camera prompted U.S. Border Patrol agents to investigate a minivan parked near the border fence and uncover a poorly built, 12-foot-long tunnel.

Tecate, Calif. Dec. 3, 2007. A sophisticated tunnel with lighting and a water pump system stretched about 1,300 feet from an office building in Tecate, Mexico to a shipping container in a dirt lot about a quarter mile north of the Tecate Port of Entry.

Nogales, Ariz. Dec. 2, 2007. A rudimentary, 10-foot-long tunnel was dug into the side of a storm drain. Border Patrol agents found it after seeing two people pushing bundles of marijuana through the tunnel from a storm grate.

Nogales, Ariz. Oct. 3, 2007. A U.S. Border Patrol agent found this small and makeshift tunnel near the port of entry. On the Mexican side, the entrance was covered with wood and under a parked car. The U.S. exit was a 4-foot by 4-foot hole cut through concrete.

Nogales, Ariz. Sept. 23, 2007. A sinkhole at the Mexican port of entry led to the discovery of this crude unfinished tunnel that went about 8 feet into the United States. The Mexican entrance was in a drain.

San Luis, Ariz. Sept. 17, 2007. U.S. Border Patrol agents found this incomplete tunnel after a water truck sank into the ground. The entrance on the Mexican side was in a home. The 250-foot tunnel was concrete-lined and shored with wood. It also had lighting and ventilation systems.

Nogales, Ariz. Sept. 7, 2007. Information from the Drug Enforcement Administration led authorities to this unfinished tunnel that was about 38 feet long. The entrance was in a Mexican house where piles of dirt were found from the tunnel construction effort.

Nogales, Ariz. July 29, 2007. A completed tunnel connected an abandoned building north of the border to a large drainage tunnel that is often bored into by smugglers trying to cross the border. It was found by the U.S. Border Patrol, and it included lights and wooden shoring.

Nogales, Ariz. July 11, 2007. DEA agents located a cross-border tunnel entrance just inside the front door a apartment on North Dunbar Street.

Nogales, Ariz. June 29, 2007. Authorities searching a warehouse found a narrow tunnel entrance that dropped down to a border drainage tunnel. More than three thousand pounds of marijuana were found inside the warehouse.

Nogales, Ariz. June 28, 2007. A completed cross-border tunnel started in a house in Mexico and connected to the laundry room of a home north of the border.

Otay Mesa, Calif. June 21, 2007. An unfinished tunnel was found by Mexican authorities about 300 yards east of the Otay Mesa port of entry.

Nogales, Ariz. April 19, 2007. A 20-foot-long tunnel was found Border Patrol agents in an apartment's kitchen. It connected to a storm drain.

Otay Mesa, Calif. March 28, 2007. Mexican authorities discovered two unfinished tunnels on the same day. The longest extended about 5 feet into the United States.

Nogales, Ariz. Feb. 8, 2007. An incomplete, 25-foot-long tunnel was discovered by General Service Administration employees filling the previously discovered tunnel with concrete.

Nogales, Ariz. Jan. 10, 2007. Border Patrol agents found a partially built tunnel after noticing some unusual sounds at an abandoned home on W. International Blvd., across the street from the border fence.

Nogales, Ariz. Jan. 6, 2007. Construction crews doing work on a driveway broke into a tunnel.

San Ysidro, Calif. Oct. 23, 2006. U.S. authorities found an incomplete tunnel just west of the San Ysidro Port of entry. It had no U.S. exit.

Otay Mesa, Calif. Oct. 10, 2006. San Diego Tunnel Task Force discovered a cross-border passageway used by a human smuggling operation. The tunnel started in a Mexican drainage system and then tapped into a concrete pipe that had once been used to deliver liquefied oxygen into the United States.

San Ysidro, Calif. Sept. 26, 2006. Mexican authorities found a tunnel that started in a junk yard controlled by Mexican Customs that went 26 feet into the United States. Two Mexican Customs inspectors were among five people arrested.

Calexico, Calif. Sept. 15, 2006. Federal authorities found a 400-foot-long tunnel about 20 feet underground that connected homes in Mexicali and Calexico. The passageway was lined with concrete, had a ventilation and water pump system.

San Ysidro, Calif. May 25, 2006. Border Patrol agents and Mexican authorities found an unfinished tunnel west of the San Ysidro Port of Entry.

San Ysidro, Calif. May 16, 2006. An incomplete tunnel was found after a portion of it collapsed. It didn't have a U.S. exit.

San Ysidro, Calif. May 12, 2006. U.S. authorities found a tunnel that had been bolstered in some sections with plastic tubing. It extended 20 yards into the United States and the exit was in a parking lot, covered with an iron plate.

Nogales, Ariz. March 4, 2006. Mexican authorities found a tunnel under construction while investigating a house linked to a suspected drug trafficker.

Nogales, Ariz. March 2, 2006. U.S. Border Patrols agents found a tunnel that emptied into in an underground drainage system after hearing voices from a water grate.

San Ysidro, Calif. Feb. 9, 2006. Mexican authorities found a partially built tunnel's entrance near the border fence, just west of the San Ysidro Port of Entry. The passageway went about 7 feet into the United States.

San Ysidro, Calif. Feb. 9, 2006. An incomplete cross-border tunnel was found near the San Ysidro border crossing. It extended from just south of the border fence to a point about 23 feet into the United States, ending at a concrete levee.

Otay Mesa, Calif. Jan. 31, 2006. Mexican authorities found a tunnel next to a previous hole that had been sealed with concrete. The tunnel extended about 3 feet into the United States, and it may not have been used.

Otay Mesa, Calif. Jan. 31, 2006. Mexican authorities found this unfinished tunnel that appeared to be heading toward a storm drain along the border.

San Ysidro, Calif. Jan. 25, 2006. A tunnel that had been partly reinforced with plastic piping was found after it had collapsed. It was approximately 50 yards west of a similar tunnel discovered on January 9

Otay Mesa, Calif. Jan. 24, 2006. A sophisticated 2,400-foot-long tunnel started at a Tijuana warehouse that hid an 85-foot-deep shaft with a pulley system used to lower drugs. It ended in a 50,000-square-foot Otay Mesa warehouse on Siempre Viva Rd.

Otay Mesa, Calif. Jan. 20, 2006. An incomplete 90-foot-long tunnel was found west of the Otay Mesa Port of Entry. The Mexican entrance was adjacent to the border fence and was concealed with a 2-foot by 2-foot board covered with dirt.

San Ysidro, Calif. Jan. 9, 2006. U.S. Border Patrol agents found this 35-foot-long tunnel just west of the San Ysidro Port of Entry after it collapsed. The 3-by-3-foot tunnel ended in a strip of vacant land near a parking lot on the U.S. side. The tunnel entrance in Mexico was across from a junkyard owned by Mexican Customs.

Otay Mesa, Calif. Nov. 16, 2005. A 50-foot-long tunnel ended just short of a drainage system on the U.S. side. This tunnel was found within a few feet of one found on August 22, 2004.

Nogales, Ariz. Oct. 31, 2005. Agents acting on an anonymous tip discovered a tunnel about 4 feet below ground that came about 50 feet into the United States from the Mexican side of the border and was only about 2 feet by 1 foot in circumference.

Nogales, Ariz. Oct. 29, 2005. Border Patrol agents discovered an incomplete tunnel near a pedestrian checkpoint when a small portion of the tunnel collapsed. The opening for this tunnel started in a house south of the border.

Nogales, Sonora. Aug. 2005. Mexican authorities found a tunnel that was linked to a drainage network along the border.

Nogales, Ariz. July 20, 2005. A 35-foot-long tunnel was found by a Border Patrol welding crew. It was heading in the direction of a warehouse and it was filled with water.

Nogales, Ariz. March 1, 2005. U.S. Border Patrol engineers doing repairs along the border found a tunnel under construction. It went 50 feet into Arizona. The tunnel was constructed using wood and steel support beams.

Calexico, Calif. Feb. 25, 2005. U.S. investigators used scanners and technology to pinpoint this 590-foot tunnel between two homes in Mexicali and Calexico. The tunnel had air conditioning, electricity, ventilation, and it was equipped with video surveillance.

Otay Mesa, Calif. Aug. 21, 2004. Mexican federal police discovered a tunnel under construction in an industrial park near the Otay Mesa crossing. It was only about 33 feet long and 1.5 feet in diameter.

San Ysidro, Calif. July 7, 2004. An incomplete tunnel was discovered originating in the same Tijuana house as a tunnel found in 2003. Contractors working for the Border Patrol found it when digging along a narrow road about 200 yards east of the San Ysidro border crossing.

San Ysidro, Calif. July 2, 2004. A cross-border tunnel that extended about 10 feet into the United States, west of the San Ysidro Port of Entry was discovered by chance. Border Patrol agents found it after driving into a 2-foot-wide sinkhole. The entry in a Mexican junkyard was hidden under a mattress.

Nogales, Ariz. Nov. 18, 2003. Mexican authorities discovered a tunnel connected to a drainage system. No further information available.

Calexico, Calif. Nov. 12, 2003. Border Patrol agents found a partially built 165-foot tunnel when it caved in underneath one of their vehicles. The tunnel had electrical and ventilation system but was filled with mud and water.

Nogales, Ariz. Sept. 12, 2003. Mexican authorities, using intelligence work and telephone surveillance, found a 1,000-foot-long tunnel that was 5 feet high and 4 feet wide. It started in a house and used a cart and rail system to transport drugs.

Calexico, Calif. Sept. 12, 2003. Calexico city crews stumbled upon a 350-foot tunnel while digging a trench. It stopped 17 feet short of a house. The tunnel had lights, ventilation, shoring and a cart system. It started in a Mexicali auto shop.

Tecate, Calif. June 6, 2003. Mexican authorities found an unfinished 40-foot tunnel in a rural area east of Tecate. The opening was in a water well, and the shaft went down about 15 feet. The tunnel was about 7 feet high and supported with wood and metal. It stopped just short of the fence and seemed to be heading toward an uninhabited house just north of the border.

San Ysidro, Calif. April 4, 2003. Border Patrol agents found a tunnel when they came across a truck in a parking lot with 3,300 pounds of marijuana. The tunnel, which had multiple twists and turns, measured between 300 and 400 feet. It started in a house just south of the border fence and it connected to a storm drain in San Ysidro. Smugglers would pass drugs from the drain opening and into the truck through a hole in the vehicle.

Nogales, Ariz. Jan. 11, 2003. An empty grave at a Mexican cemetery was the starting point for this tunnel, which connected to an underground water drainage system that allowed for access to the United States.

Nogales, Ariz. Dec. 27, 2002. Authorities discovered a 165-foot tunnel that was 3 feet tall by 4 feet wide. It had a concrete pavement.

Otay Mesa, Calif. Dec. 2, 2002. Mexican authorities found a tunnel entrance underneath a Tijuana house, a block from the border. The tunnel shaft plunged 59 feet underground, but hadn't been built farther.

Imperial Beach, Calif. April 2, 2002. An incomplete 65-foot-long tunnel was being dug into a rocky hillside along the border. U.S. Border Patrol agents found it.

Nogales, Ariz. April 15, 2002. This 85-foot-long tunnel ended near a parking lot. It was discovered after a security guard noticed an odd depression in the ground.

Tecate, Calif. Feb. 27, 2002. A highly sophisticated 1,250-foot-long tunnel started behind the fireplace of a ranch house 20 miles east of Tecate, Mexico. It ended in a house in the Tierra del Sol community north of the border, near Boulevard. It included lighting, ventilation and rails for electric cars. Inside the tunnel was 297 pounds of marijuana.

Nogales, Ariz. Jan. 21, 2002. Mexican police officers found people working on a tunnel.

Nogales, Ariz. Dec. 1, 2001. Tunnel started in a concrete wash along the border and ended in a house about 40 feet north of the border.

Nogales, Ariz. Sept. 4, 2001. Mexican federal authorities found a tunnel entrance after they found four people digging 8 feet underground, near a concrete wash.

Nogales, Ariz. Feb. 28, 2001. A 30-foot-long tunnel started in a Nogales concrete wash and was shored with plastic piping to its exit point on property adjacent to a car wash, about a half mile from the border. Marijuana was found inside.

Nogales, Ariz. Feb. 26. 2001. A crude tunnel that was about 25 feet long started in a sewer system linked to a Nogales wash and ended at a house. About 840 pounds of cocaine were found.

Nogales, Ariz. June 29, 2000. Tunnel ended in a house north of the border.

Nogales, Ariz. May 16, 2000. No additional information available.

Nogales, Ariz. Oct. 21, 1999. Tunnel connected a house to a storm drain.

Naco, Ariz. May 1, 1999. Tunnel connected a house in Naco, Mexico, to a mobile home north of the border. It was about 90 feet long.

Nogales, Ariz. Jan. 20, 1999. This tunnel went from an apartment near the exit point of the 200-foot tunnel (found the same day) toward a nearby church. This tunnel's exit point was initially undetermined because of an obstruction in the tunnel.

Nogales, Ariz. Jan. 20, 1999. This 200-foot-long tunnel, which started in a drainage system near the border and ended in a house, included lighting and a cooling system.

Otay Mesa, Calif. Aug. 1, 1998. This passageway used portions of the tunnel found here in June 1993.

Nogales, Ariz. Sept. 1, 1995. Exit for this passageway was in an abandoned church.

Otay Mesa, Calif. May 31, 1993. A nearly completed tunnel was discovered with an entrance a Tijuana warehouse It plunging 65 feet underground and stretched 1,452 feet, stopping just 120 feet short of an Otay Mesa warehouse on Siempre Viva Road. It included electrical power and air conditioning.

Douglas, Ariz. May 17, 1990. The first sophisticated cross-border drug tunnel to be discovered had lights and a rail system for carts, and stretched about 300 feet from Agua Prieta, Sonora, to Douglas, Ariz. The starting point was under a pool table in a Mexican house. To open the tunnel entrance, water was turned on from an outside spigot. A hydraulic pump system forced a section of the concrete floor to rise about 8 feet. The tunnel's exit point was a false drain inside a warehouse. At least 2,250 pounds of cocaine may have been smuggled through it before it was found, according to an investigation. The tunnel is suspected to have been built for a drug group headed by suspected trafficker Joaquin Guzman Loera.

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