If disaster had struck Donald Trump's inauguration, where most members of the legislative, executive and judicial branches gathered at the Capitol, outgoing Homeland Security Secretary Jeh Johnson would have become president of the United States.
Johnson, the Cabinet member selected as the designated survivor during President Barack Obama's final State of the Union address last year, reprised his role during the 45th president's inauguration.
It's typically associated with State of the Union addresses, but every four years on Inauguration Day, the outgoing or incumbent administration selects a designated survivor who would be prepared to take the oath of office if necessary. The White House keeps the identity of the chosen one a secret until the day of the event, and the person's location remains a mystery until the all-clear.
The nation's nuclear launch codes, a 45-pound briefcase known as "the football," also travels with the designated survivor. And rest assured, whoever has it has undergone training to step into the president's shoes.
