American cities present a target-rich environment for the terrorist. The urban setting provides access to a set of highly integrated infrastructure systems—such as water, electrical, and gas supplies; communications; and mass transit—as well as to numerous major buildings and places of public assembly.

Major buildings have been recognized as especially attractive targets, and, based on the events of September 11, they have also become the subject of serious structural reexamination—in particular, to determine what weaknesses must be corrected to prevent catastrophic collapse following an attack, as happened with the twin towers of the World Trade Center. Study of the information coming from the failure of those buildings indicates that research and development leading to improved blast- and fire-resistant designs should be undertaken by NIST, the national laboratories, Underwriters Laboratories, the National Fire Protection Association, and appropriate code-writing organizations. In the near term, while results of this research and development are being realized, provisional guidelines may be issued that are based on the more advanced fire-rating practices now employed in Europe, Australia, and New Zealand. The results of this work should be disseminated so that new knowledge is incorporated into the codes and standards for the design and construction of new buildings and for remodeling the existing stock as well. Specific testing programs are recommended in Chapter 8, with particular attention given to methods and materials for fire protection and to connections and curtain walls.

Major buildings are also vulnerable to infectious or toxic materials being circulated by heating, ventilation, and air-conditioning (HVAC) systems after their release into the air. To counter this threat, it is necessary that NIST, perhaps together with other agencies and the national laboratories, undertake a research and development program for sensors that can be installed in the air-handling ducts. These sensors could determine whether air is safe or not, and allied controls could adjust the functioning of HVAC systems accordingly.

The heart of a city’s response to a terrorist attack is an emergency operations center (EOC) and the first responders—those who are typically dispatched to the scene of a problem before the EOC can determine its nature or cause. An urgent near-term task is to develop credible terrorist-threat scenarios that EOC teams can prepare to meet. Further, a technical assessment of the adequacy of an EOC’s physical facilities to address and survive these threat scenarios should be performed.

The ability of first responders to quickly determine if the dust and smoke at a site contain toxins will likely mean the difference between life and death. It is important that research and development be undertaken with the aim of producing new, small, reliable, and quick-reading sensors of toxic materials for use by first responders. These devices might be based on the same core element as the sensors recommended for HVAC systems.