U.S. authorities say a cross-border tunnel ran the length of four football fields from a restaurant in Mexicali, Mexico, to a house in Calexico.
Investigators seized the tunnel Wednesday following an investigation that netted more than a ton of marijuana and resulted in four arrests in California and Arizona.
Prosecutors say drug traffickers finished building the Calexico house in December and began smuggling drugs there last month under law enforcement surveillance.
It is the 12th completed drug tunnel that authorities have found along California's border with Mexico since 2006. In the last five years, authorities detected 75 border tunnels, mostly in California and Arizona and many of them incomplete.
