Authorities say a 73-year-old grandmother is behind a sophisticated drug tunnel discovered on the border of the United States and Mexico in California.

ICE agents arrested Glennys "Gladys" Rodriguez, of Chula Vista, Calif., who is accused of overseeing the tunnel’s construction.

The tunnel was discovered inside a warehouse on Tuesday after a months-long investigation. It was about 600 yards long and equipped with lighting, a rail system and wooden trusses. ICE officials say Rodriguez hid the entrance behind boxes of televisions and plastic children’s toys.

A second tunnel, measuring 700 yards long and equipped with a multi-tiered electric rail system, was found on Thursday.

Authorities believe the tunnels were going to be used to smuggle pot and cocaine into the United States. Agents can’t say how much drugs moved through the tunnels before they were found.

“Here we are again, foiling cartel plans to sneak millions of dollars of illegal drugs through secret passageways that cost millions of dollars to build,” U.S. Attorney Laura Duffy said. “Going underground is not a good business plan. We have promised to locate these super tunnels and keep powerful drug cartels from taking their business underground and out of sight, and once again, we have delivered on that promise.”

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