[Excerpt] On September 11, 2001, life as we knew it changed when a terrorist attack took the lives of thousands with the hijacking of four airplanes. Two of those planes were used to destroy the World Trade Center’s Twin Towers. Many changes have taken place since September 11. The events of September 11 have had an impact on the US office market. This paper will focus on changes to corporate real estate strategic planning and changes to urban high-rise office buildings that have emerged as a response to September 11. Corporate strategy changes that will be discussed will focus on decisions made with respect to the geographic location of human capital, new security measures taken, and business continuity strategies which focus on changes to data storage practices. Changes to physical characteristics of high-rise office buildings will be discussed, emphasizing the changes taking place in the future design and construction of buildings due to architectural, structural, and technological changes and changes in the management and operation of buildings. First we will take a look at the overall office market post September 11 and then will focus on the specific changes that have taken place since that time.