article_snippet.sent: The 66ft deep route, which was still under construction and was being built next to the Tijuana checkpoint, was wired with lights and ventilation.
article_snippet.sent: Officials said The 66ft deep route, which was still under construction and was being built next to the Tijuana checkpoint had not yet crossed the U.S. border and only stretched some 500 feet.
article_snippet.sent: But officials believe if it had been left undiscovered it would have surfaced somewhere just inside U.S. territory.
article_snippet.sent: the U.S. border is just over 22 miles from the city of San Diego, California.
article_snippet.sent: The route had not yet reached U.S. soil, but if The route went undiscovered official believe The route would have surfaced a short distance from the U.S. border .