Federal agents seized $29.6 million worth of illegal drugs from a tunnel used by smugglers to enter San Diego from Mexico, a cross-border passageway so sophisticated that it had ventilation, lighting and an underground rail system, authorities said today.

The tunnel’s entrance was not far from a newly constructed border wall that President Donald Trump visited in September in the Otay Mesa section of San Diego.

The stockpile of drugs included 1,300 pounds of cocaine, 86 pounds of methamphetamine, 17 pounds of heroin, 3,000 pounds of marijuana and more than 2 pounds of fentanyl, the San Diego Tunnel Task Force said.

The task force is made up of agents from Immigration and Customs Enforcement, the Drug Enforcement Administration and Border Patrol, which said the 2,000-foot-long tunnel was discovered March 19.

“These tunnels show the determination of drug trafficking organizations to subvert our border controls and smuggle deadly drugs into our community,” John W. Callery, a DEA special agent in charge, said in a statement today.

There were no arrests in the seizure, which authorities said was part of a developing investigation. They said the seizure was one of the largest hauls of illegal drugs found in a single tunnel in recent memory.

The discovery came a little over two months after a 4,309-foot-long tunnel was found in the same area, one that federal agents said was the longest tunnel ever found along the southwestern border of the United States.

“Cross-border tunnels represent one of the most significant threats to our national security,” Aaron M. Heitke, a chief Border Patrol agent, said in a statement today. “Criminal organizations can use these tunnels to introduce anything they want into the U.S. This is especially concerning during a global pandemic.”

Authorities said that the average depth of the tunnel, which connected warehouses in Otay Mesa and Tijuana, Mexico, was 31 feet. Federal agents said the 3-foot-wide tunnel had existed for several months and was discovered after the task force had learned of a narcotic smuggling operation by a transnational criminal organization. They did not name the organization.

“If cartels keep spending millions of dollars building tunnels, we will keep finding and filling them,” Robert S. Brewer Jr., U.S. attorney for the Southern District of California, said in a statement today.

Jeff Stephenson, a supervisory Border Patrol agent, said in an email today that the tunnel was in the same area as a double-layered wall system where an upgrade had begun in March 2018 and was scheduled to be completed later this year. He said that more than 70 tunnels had been discovered in the San Diego area since 1993.

It was not immediately clear if the drug smugglers dug the tunnel before or after the new border wall was constructed.

Building a border wall has been a focus of Trump’s, who made the issue a bedrock of his 2016 presidential campaign. Critics of Trump’s wall initiative have said that the barrier is an ineffective way to secure the border and that it can be subverted by tunnels.

During a visit to Otay Mesa in September, Trump signed his name to one of the steel slats on a newly constructed barrier and boasted that it would be the most impenetrable wall in the world.

“The wall has a ways to go, but we’re building it at breakneck speed,” Trump said at the time, surrounded by Border Patrol agents and construction workers. “When this is completed,” he added, “there won’t be a border anywhere like this.”

The White House said it was not immediately prepared to comment today.

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