|Why your wall is expensive and useless.|
How the Sinaloa drug cartel digs its tunnels.
"Guzmán’s method of escape should have surprised no one. Last year, in Culiacán, he evaded Mexican marines by disappearing into a network of subterranean passageways connecting seven houses. He did not invent smuggling tunnels—bank robbers, rumrunners, and guerrillas had used them for decades—but his criminal enterprise, the Sinaloa drug cartel, built the first cross-border narcotúnel, in 1989. Since then, Sinaloa has refined the art of underground construction and has used tunnels more effectively than any criminal group in history."