On the morning of Saturday, February 20, 1971, Wayland S. Eberhardt, a civilian teletype operator, was going about his routine duties at the National Emergency Warning Center at Cheyenne Mountain in Colorado. One of the functions of “the Mountain” during this era was to send out the weekly Emergency Broadcast System (EBS) test directive to the nation’s radio and television stations. They were, of course, also responsible for sending out the real warning. When stations received these messages they compared it against a card to determine what action to take.
At 7:33 a.m. local time on that fateful Saturday, Mr. Eberhardt, a fifteen-year veteran of his job, fed the wrong tape into the transmitter and set off a panic that is remembered to this day. He was later quoted by the New York Times as saying “I can’t imagine how the hell I did it.” But he did.
After forty minutes of frantic scrambling and sending out “kill” messages that did not contain an authenticator code word, the Cheyenne Mountain staff finally found the correct code to cancel the apocalyptic transmission.