On the clear, cool morning of November 13, 1963, a convoy flanked by blue Air Force police cars with flashing lights turned off the tarmac at Kelly Air Force Base, southwest of downtown San Antonio. It wound its way carefully across Interstate 410 and into the neighboring Lackland Air Force Base’s Medina Annex, slowly passing a neighborhood made up of new ranch homes.
At the center of the convoy, an ungainly vehicle called a straddle carrier, whose driver sat in a cab high above the roadway, held precious cargo slung between its four wheeled legs. The vehicle resembled a giant spider protecting its eggs.
The convoy drove into Site King, a secret area in Medina where about a hundred humpbacked rectangular bunkers made of fortified steel and concrete, known as “igloos”—each roughly the size of four 2-car garages—served as one of the country’s largest nuclear weapons installations.