O’Rourke headed the team analyzing the impact of attacks against New York City on September 11, 2001 and presented the team's findings at a National Science Foundation (NSF) workshop on December 12 and 13, 2001. The workshop was organized by the Institute for Civil Infrastructure Systems (ICIS), of which Professor O'Rourke was the executive committee's co-chair. The assessment concluded that the infrastructure of New York City survived the attack remarkably well, and a study team was created to determine what attributes of American engineering led to such resilience.