Terrorism is something the United States of America has had to deal with since 1789. Near the end of the 20th century such attacks had become more frequent and devastating with the most casualties caused by a single individual with the Oklahoma City bombing in 1995. This has led to a nationwide uncertainty if more buildings were at risk to be damaged and how could this be prevented in the future. This thesis will analyze what changes are made in designing after a terrorist attack to determine how we approach structural and safety design differently. For this analysis The World Trade Center bombing (1993), The Oklahoma City bombing (1995) and The September 11 attacks (2001) will be discussed. In all 3 cases most changes were made in order to either improve structures to isolate damage at the location of the blast or to improve the safety of people in the building at the moment of an attack or during the evacuation.