The latest drug tunnel discovered between Tijuana and San Diego featured ventilation, lighting and a rail system capable of moving loads of wrapped marijuana across the border. Within hours of launching operations on Wednesday, the passageway was shut down, 22 suspects were under arrest and 12 tons of marijuana had been seized by U.S. and Mexican authorities.

“We believe with a pretty good degree of certainty that the marijuana loads that began moving yesterday morning were the first drugs that moved through this tunnel,” U.S. Attorney Laura Duffy said Thursday.

× Suspects Arrested, Pot Seized at Drug Tunnel

The tunnel, about a half-mile in length, was one of the largest found in the area in recent years. It was described by U.S. officials as one of 10 sophisticated passageways uncovered in the area since 2006 capable of moving large amounts of narcotics from Mexico to the United States.


Several major drug tunnels on the California border in recent years have been attributed to the Sinaloa Cartel, whose leader Joaquin “El Chapo” Guzman escaped from a maximum-security prison outside Mexico City in July through an elaborate tunnel. But detainees at the drug tunnel entrance in Tijuana told authorities there that they had been working for a criminal group operating in the state of Jalisco.

David Shaw, special agent in charge of Homeland Security Investigations in San Diego, said Thursday that the investigation was continuing and that “we’re not ready to make a public statement on that yet.”

U.S. authorities said the tunnel’s discovery on Wednesday came after an investigation launched last May in San Diego by HSI involving two undercover agents.

According to court documents, an undercover homeland security agent made contact with one of the suspects, a 53-year-old Mexican citizen named Isaias Enriquez Acosta. The undercover agent was told that drivers would receive $10,000 per load to move “stuff,” which he understood to be drugs, from a warehouse near the U.S. border.


The warehouse turned out to be the tunnel’s U.S. exit in a building on Otay Center Drive near Customhouse Plaza, just west of the Otay Mesa Port of Entry.

1 / 24 Officials said the tunnel discovered in Otay Mesa in April 2016 was sophisticated, containing a ventilation and railing system. ( / U.S. Attorney’s Office) 2 / 24 The cross-border tunnel that connected a Tijuana flophouse and an Otay Mesa yard was narrow, at only 3 feet across in most sections. It was discovered in April 2016. ( / U.S. Attorney’s Office) 3 / 24 The Otay Mesa tunnel discovered in April 2016 was lighted as well. ( / U.S. Attorney’s Office) 4 / 24 Police at the Mexican side of drug tunnel discovered west of Otay Mesa border crossing on Wednesday, October 21, 2015. (Mexican Federal Police) 5 / 24 This Wednesday, Oct. 21, 2015 photo released by Mexico’s Federal Police shows an underground tunnel that police say was built to smuggle drugs from Tijuana, Mexico to San Diego in the United States. Mexican federal police said the tunnel extends about 2,600 feet (800 meters) and is lit, ventilated, equipped with a rail car system, and lined with metal beams to prevent collapse. (Mexico Federal Police via AP) (The Associated Press) 6 / 24 Mexican side of drug tunnel discovered west of Otay Mesa border crossing on Wednesday, October 21, 2015. (Mexican Federal Police) 7 / 24 Federal authorities discovered two cross-border drug smuggling tunnels in Otay Mesa in early April. At one, U.S. agents had a surprise encounter with what some said were armed men in military garb. (ICE) 8 / 24 An incomplete tunnel discovered early Tuesday by the U.S. Border Patrol west of the San Ysidro Port of Entry had lighting and a rail system. ( / U.S. Immigration and Customs Enforcement) 9 / 24 A tunnel leading from Mexico into the United States was discovered by agents from El Centro Sector Border Patrol’s Border Search Trauma and Rescue unit. ( / U.S. Customs and Border Protection) 10 / 24 A drug tunnel was discovered Tuesday in Tijuana near the airport. ( / Segunda Zona Militar) 11 / 24 In this undated photo provided by the United States Drug Enforcement Administration, shows the tunnel shaft entrance on the U.S. side of a 240-yard, complete and fully operational drug smuggling tunnel that ran from a small business in Arizona to an ice plant on the Mexico side of the border, Thursday, July 12, 2012, in San Luis, Ariz.(AP Photo/Drug Enforcement Administration) ( / AP) 12 / 24 This image provided Thursday July 12, 2012, by the U.S. Immigration and Customs Enforcement shows a tunnel discovered by authorities designed to smuggle drugs into the United States, found in Tijuana, Mexico. An Immigration and Customs Enforcement spokeswoman said Thursday that the approximately 220-yard passage was lit and ventilated. It began under a bathroom sink inside a warehouse and did not cross the border into San Diego.(AP Photo/ICE) ( / AP) 13 / 24 In this undated photo provided by the United States Drug Enforcement Administration, shows 39 pounds of methamphetamine smuggled through a 240-yard, complete and fully operational drug smuggling tunnel that ran from a small business in Arizona to an ice plant on the Mexico side of the border, Thursday, July 12, 2012, in San Luis, Ariz.(AP Photo/Drug Enforcement Administration) ( / AP) 14 / 24 In this undated photo provided by the United States Drug Enforcement Administration, shows a 240-yard, a complete and fully operational drug smuggling tunnel, from the U.S. side of the tunnerl, that ran from a small business in Arizona to an ice plant on the Mexico side of the border, Thursday, July 12, 2012, in San Luis, Ariz.(AP Photo/Drug Enforcement Administration) ( / AP) 15 / 24 In this undated photo provided by the United States Drug Enforcement Administration, shows floor shaft entrance from a storage room that was a 240-yard, a complete and fully operational drug smuggling tunnel that ran from a small business in Arizona to an ice plant on the Mexico side of the border, Thursday, July 12, 2012, in San Luis, Ariz.(AP Photo/Drug Enforcement Administration) ( / AP) 16 / 24 View from inside a tunnel recently found in the northern border city of Tijuana, Mexico, Wednesday Nov. 30, 2011. A day earlier, the tunnel was discovered by U.S. authorities in San Diego’s Otay Mesa area, the latest in a spate of secret passages found to smuggle drugs from Mexico. This tunnel is a 600-yard passage linking warehouses in San Diego and Tijuana and is equipped with lighting and ventilation. (AP Photo/Alex Cossio) ( / AP) 17 / 24 View from inside a tunnel recently found in the northern border city of Tijuana, Mexico Wednesday Nov. 30, 2011. A day earlier, the tunnel was discovered by U.S. authorities in San Diego’s Otay Mesa area, the latest in a spate of secret passages found to smuggle drugs from Mexico. This tunnel is a 600-yard passage linking warehouses in San Diego and Tijuana and is equipped with lighting and ventilation. (AP Photo/Alex Cossio) ( / AP) 18 / 24 A news photographer walks inside a tunnel in the northern border city of Tijuana, Mexico Wednesday Nov. 30, 2011. A day earlier, the tunnel was discovered by U.S. authorities in San Diego’s Otay Mesa area, the latest in a spate of secret passages found to smuggle drugs from Mexico. This tunnel is a 600-yard passage linking warehouses in San Diego and Tijuana and is equipped with lighting and ventilation. (AP Photo/Alex Cossio) ( / AP) 19 / 24 Mexican soldiers on Wednesday stood near a 28-foot shaft leading to an elaborate clandestine drug tunnel connecting warehouses on both sides of the border. (John Gibbins) 20 / 24 This image provided by the San Diego Tunnel Task Force shows the entrance to a cross-border tunnel in San Diego on Tuesday Nov. 29, 2011, the latest in a spate of secret passages found to smuggle drugs from Mexico. The tunnel was found in San Diego’s Otay Mesa area, a warehouse district across the border from Tijuana, according to authorities. (AP Photo/San Diego Tunnel Task Force) ( / AP) 21 / 24 This image provided by the San Diego Tunnel Task Force shows the entrance to a cross-border tunnel in Tijuana on Tuesday Nov. 29, 2011, the latest in a spate of secret passages found to smuggle drugs from Mexico. () 22 / 24 There was an electric operated car sled that could have several cars connected to it to move drugs to the north.. (John Gibbins) 23 / 24 Some of the drugs smuggled through the cross-border tunnel discovered in Otay Mesa in April 2016. The tunnel was sophisticated, containing a ventilation and railing system. ( / U.S. Attorney’s Office) 24 / 24 The tunnel’s exit, found in an Otay Mesa lot. ( / U.S. Attorney’s Office)

The undercover HSI agent and a companion picked up their first load at about 7:15 a.m. Wednesday, and drove it to the second warehouse at an undisclosed location. There, they unloaded about 249 bundles of a “green leafy substance containing the strong odor of marijuana and wrapped in clear plastic,” according to the court documents.

Later in the day, at about 11:15 a.m. at a restaurant in San Diego, the homeland securityagent met with Enriquez and a second suspect, a 27-year-old Mexican citizen named Isidro Silva Acosta. There, they made arrangements to move a second load.


But at 5:30 p.m., 30 agents with HSI’s Special Response Team moved in on the Otay Center Drive warehouse, arresting Silva, according to a news release from the U.S. Attorney’s Office. Enriquez was arrested at a nearby hotel, it said.

Inside the warehouse, agents found a hole about 3 feet in diameter that dropped down about 32 feet and led to an underground tunnel. Peering inside the passageway, agents saw additional plastic-wrapped bundles. By Thursday, the U.S. agents had seized close to 2 tons of marijuana from the warehouse and the tunnel.

Silva and Enriquez were arraigned Thursday in federal court. They were charged with unlawful conspiracy to import a controlled substance and conspiracy to use border tunnels and passages.

Duffy said four additional suspects were arrested by the San Diego County Sheriff’s Department, “in connection with the movement of the marijuana from the undercover warehouse” to various San Diego residences and businesses.


Duffy said they would be charged by the San Diego District Attorney’s Office. Both the District Attorney’s Office and the Sheriff’s Department declined to reveal the suspects’ names on Thursday.

In Mexico, Federal Police announced the arrests of 16 suspects at a warehouse that covered the tunnel’s Tijuana entrance south of the border fence. A statement said that “an intense movement of trucks and vans came and went,” from that location, “apparently to drop off drugs for their transfer to the United States.”

The suspects, ranging in age from 21 to 50, told federal prosecutors that their task was to wrap the marijuana and send it, the statement said. All but one of the detainees said they were from the state of Sinaloa.

The passageway dropped about 30 feet from the warehouse, according to Mexican authorities. The tunnel was shored up with metal tubes, to avoid its collapse, they said. It included lights and ventilation, and a rail system to move the drugs. According to preliminary calculations, the tunnel measured about 2,600 feet, with three-fourths of its extension in Mexican territory.


Authorities seized 873 packages weighing about 10 tons that were apparently ready to be moved to the United States, the statement said.

U.S. authorities have detected more than 80 cross-border smuggling tunnels in the last five years, with most of them in California and Arizona.

The clay soil of the Otay Mesa area offers stability for cross-border tunnels that would be more likely to crumble in sandy soils found elsewhere, U.S. authorities say. The area also has warehouses on both sides of the border, making it easy to blend in, Duffy said, and quick routes to interstate highways to transport the drugs.