Abstract: A collapsible ladder assembly for emergency exit from a building is secured to a window opening by a pair of anchoring hooks and includes two pairs of spaced-apart flexible rail members which support both a generally rectangular top step and a generally rectangular lower step at the four corners thereof. A plurality of intermediate rungs are supported by one of the pairs of rail members away from the building to provide for easier foot placement of the person descending the ladder. The top step defines a cavity for receipt of the rungs and the lower step in a stored condition.