Power in western New York was restored in a few hours, thanks to the Genesee River-powered generating plant in Rochester, which stayed online throughout the blackout. Like starting a car, to start or restart a generator requires power for a starter motor (see black start). The availability of this hydroelectric power was crucial; it was used to restart dead generators, which then could provide power to restart other generators, in a cascading process which required much switching by engineers at the various plants.