The Border Patrol continues to discover tunnels under the U.S.-Mexico border in, shall we say, a low-tech manner.
The most recent Border Patrol press release on the discovery of a tunnel said, in effect, that one of its agents encountered the tunnel when the ground opened up before him, or to quote the release:
As the agent approached the anomaly [a depression] in the soil on foot, it began to give way exposing a hole 18 inches in diameter.
This happened along the border two miles east of the Calexico port of entry, in southern California. The three-by-three tunnel was about 142 feet long, with 82 feet of it under U.S. soil.
The Border Patrol recently learned of another tunnel in Nogales, Ariz., when Mexican authorities told them about it.
Apparently the Border Patrol's high-tech tool kit does not include any reliable devices to record underground digging at the border.