U.S. federal officials say the cross-border tunnel they discovered Monday afternoon does not have an exit on the San Diego side. As KPBS Reporter Amy Isackson explains federal officials say the tunnel tapped into the drainage system.
Immigration and Customs Enforcement spokeswoman Lauren Mack says the people digging the tunnel popped open a manhole in Tijuana a few feet from the border fence.
She says they crawled through the pipe underneath the fence and tapped into the sewage system on the US side.
Mack says the diggers then used a homemade ladder to climb into another drain pipe, broke out of that one, and bored through the dirt.
"The concern that somebody understands the structure as well as it appears they do is alarming. That they're able to talk immigrants into going into these systems and trusting that they're going to be safe is equally alarming."
Mack says smuggling through storm drains has been on the rise in San Diego for the last year.
She says historically smugglers use drain tunnels for immigrants and small amounts of marijuana.
