STEVE INSKEEP, HOST:
In San Diego, authorities have unearthed what they say is the most sophisticated drug smuggling tunnel they have ever found along the U.S.-Mexico border. Reporter Amy Isackson in San Diego says it's the second found, just this month.
AMY ISACKSON, BYLINE: The tunnel runs between two non-descript warehouses - one in Tijuana, the other in an industrial area of San Diego. Derek Benner heads Immigration and Customs Enforcement in San Diego.
DEREK BENNER: The tunnel we're describing today has reinforced walls and a solid wood floor.
ISACKSON: It's so elaborate it even has an elevator at its entrance in Tijuana. The Mexican Army let reporters ride down into the tunnel's depths, where it was hard even to talk. There's enough space to get through it kind of hunched over. It's musty. It smells damp. And it's warm. There's train tracks that run the length of the tunnel.
LAURA DUFFY: If you build it, we'll find it.
ISACKSON: Laura Duffy is the U.S. Attorney in San Diego.
DUFFY: And when we find it, we'll destroy it.
ISACKSON: Authorities seized about 34 tons of marijuana and arrested six people. It's the third year in a row that officials have busted a tunnel around this time, just after the marijuana harvest and when smugglers are rushing to move their product to market so they don't have to work over the holidays.
For NPR news, I'm Amy Isackson in San Diego.
(SOUNDBITE OF MUSIC)
INSKEEP: This is NPR News. Transcript provided by NPR, Copyright NPR.