Urban sprawl has increased the frequency with which windstorms interact with structures. The Lubbock Storm (May 11, 1970) and Hurricane Celia (August 3, 1970) provide the most recent examples of storm incidence on populated areas. The responses of engineered structures to extreme winds are characterized by window glass breakage and failures of nonstructural components, each of which can lead to progressive failures of the structure. Pre-engineered buildings experience wind induced progressive failures because of overhead doors which are not designed as integral parts of the structure. Failures in pre-engineered buildings include buckling of purlins and girts throughout the structure due to wind induced outward pressures, and buckling of purlins spanning between end frames and first interior frames due to wind induced axial load. Marginally engineered structures (including residences and some light commercial buildings) experience wind induced failures which are the result of inadequate connections between roofs and walls, and between walls and foundations, i.e., the result of the buildings not being designed as integral structures.