SeaTac Airport is a critical element of the Pacific Northwest's regional infrastructure. With nearly 500 aircraft landings each day, SeaTac is among the busiest airports in the nation. In order to assess the vulnerability of this essential facility and determine the first steps to take in mitigating seismic risk, the Port of Seattle hired Reid Middleton to prepare a comprehensive report outlining the seismic risk associated with each of the airport's terminal buildings. Reid Middleton performed seismic evaluations, determined the relative level of seismic risk, and assessed seismic retrofit feasibility for Concourses A, B, C, and D; the Main Terminal Building; and the North and South Satellite terminal buildings.