Abstract: This invention is an interlocking, segmented, ladder for use on high rise buildings and the like; wherein, the ladder is stored horizontally between floors of such building so as to not create an unpleasant or dangerous permanent exterior structure, and wherein the ladder may be automatically or manually actuated in the event of an emergency, in which case each section is extended from its horizontal position of storage within the building and is rearranged in a vertical position on the exterior of the building; and, appropriate safety footings are provided for inter-locking of the various elements; and, a series of safety devices are incorporated so that persons using the ladder will not fall from it and provisions are made for safe entrance onto the ladder.