https://www.newyorker.com/magazine/2015/08/03/underworld-monte-reel
How the Sinaloa drug cartel digs its tunnels.
At 8:52 P.M. on July 11th, Joaquín Guzmán Loera, the drug kingpin known as El Chapo, sat on the bed of his cell in Altiplano, Mexico’s only super-maximum-security prison. Surveillance footage appears to show a small screen glowing on a table nearby—inmates are not allowed cell phones, but this rule is not always enforced. Guzmán changed his shoes, walked to a shower area in the corner of the cell, and knelt behind a waist-high concrete partition, out of view of security cameras. Six seconds later, he was gone.
A rough-edged opening, about twenty inches square, had been cut into the floor. According to Mexico’s national-security commissioner, Guzmán climbed into the hole and down a ladder, entering a 4,921-foot-long tunnel. Fluorescent lights hung from a ceiling-mounted PVC pipe, which also brought fresh air into the passageway. Metal tracks had been bolted to the ground, allowing an ad-hoc vehicle—a railcar rigged to the frame of a small motorcycle—to be driven from one end of the tunnel to the other. The gray stone walls, about thirty inches apart, were scored with jagged marks made by electric spades; Guzmán’s shoulders probably brushed the walls as he passed.