Abstract: An escape system for multi-story buildings comprising ladder units secured to the building at successive levels thereof adjacent an exit opening such as a window. Each unit comprises a housing and a collapsible ladder section having one end anchored therein and an actuating lever accessible from the window or to a person on the ladder section above for releasing the ladder section so that it falls by gravity to an extended position reaching to the next lower ladder unit. The lower end of a ladder section can be secured to the upper end of the ladder section in the next lower unit.