designated survivor

In the United States, a designated survivor (or designated successor) is a named individual in the presidential line of succession, chosen to stay at an undisclosed secure location, away from events such as State of the Union addresses and presidential inaugurations. The practice of designating a successor is intended to prevent a hypothetical decapitation of the government and to safeguard continuity in the office of the president in the event the president along with the vice president and multiple other officials in the presidential line of succession die in a mass-casualty incident. The procedure originated in the 1950s during the Cold War with its risk of nuclear attack.