The Great Blackout was a worldwide, nuclear-produced EMP blackout that began during the Great War and lasted for an unknown period of time after the War.
The Blackout seems to have stopped most, if not all, functioning vehicles and most electronics. When Salt Lake City was hit directly with thirteen nuclear warheads, Randall Clark's truck and a passing Chryslus car came to an abrupt stop. According to the Shi Emperor a Chinese People's Liberation Army navy submarine, Shi-huang-ti, washed ashore in the San Francisco bay area after it ceased to function due to the Blackout. Staff Sergeant Michael Daly's Vertibird crashed on the rooftop of the Museum of Freedom in Concord, Boston due to the Great Blackout, and several airplanes crashed in the area surrounding Boston Airport.