A few minutes later the order was rescinded. The B-52 circling Thule had made contact with the base. It had not been destroyed by the Soviets. An investigation subsequently found that the failure of a single AT&T switch in Black Forest, Colorado, had shut down all the ballistic missile early warning circuits, voice communications between the SAC and NORAD command posts, and the “hot line” linking SAC’s commander to NORAD headquarters. AT&T had neglected to provide redundant circuits for some of the nation’s most important communications links, despite assurances that it had done so.
