OTAY MESA, California (Storyful/KFOR) – Just after midnight on Friday the 13th, a federal drug investigation led investigators to what they called a “sophisticated” cross-border tunnel from Tijuana, Mexico to Otay Mesa, California – complete with a rail system, electricity, ventilation, reinforced walls, and lots and lots of drugs.

Video from US Immigration and Customs Enforcement shows federal and state authorities descending into the 61-foot-deep tunnel, that stretched for one-third of a mile. The four-foot-wide tunnel had investigators crawling on their knees at one point.

The 1,744-foot-long tunnel opened to a warehouse in Otay Mesa, approximately 300 feet north of the U.S.-Mexico border. During the investigation, authorities arrested six people, and seized 1,762 pounds of cocaine, 164 pounds of methamphetamine, and nearly four pounds of heroin.

“There is no more light at the end of this narco-tunnel,” said U.S. Attorney Randy Grossman. “We will take down every subterranean smuggling route we find to keep illicit drugs from reaching our streets and destroying our families and communities.”

Since 1993, 90 underground tunnels have been discovered in Southern California. Of those, 27 were considered sophisticated.

All six defendants face ten years to life in prison, plus up to a $1 million fine, if convicted.