Officials find 'most sophisticated tunnel in U.S. history' between Mexico and Arizona

Federal officials said they discovered an underground tunnel traveling across the U.S.-Mexico border into Arizona that they said appears to be the “most sophisticated tunnel in U.S. history.”

Agents with U.S. Immigration and Customs Enforcement (ICE) discovered the unfinished tunnel after excavating outside of Yuma, Ariz., as part of an ongoing multiagency investigation led by ICE's Homeland Security Investigations (HSI) arm.

The passage was found to be 3 feet wide and 4 feet high and was equipped with a fully developed ventilation system, water lines, electrical wiring, rail system, extensive reinforcement and shoring.


“This appears to be the most sophisticated tunnel in U.S. history, and certainly the most sophisticated I’ve seen in my career,” Carl Landrum, acting chief patrol agent with the Border Patrol’s Yuma Sector, said in a news release. “We will continue to work closely with our partners – Homeland Security Investigations and state and local agencies to provide the best national security possible.”

Investigators started excavating around the tunnel late last month after a sinkhole was reported near the border wall. HSI had already received reports of tunnel activity in the area.

It was not immediately clear what the tunnel was being used for since it was incomplete, but smugglers are known to use underground passages beneath the border to move drugs, people and other materials.