location, as was the case in New York on 9/11. Here again, established plans and well-practiced teachers and students minimized the harm that came to the children. The best defense is to be prepared.
The reaction of stadiums to the impact of an aircraft or to explosions from any source needs to be better understood. In addition, in so far as current technology and the designs of current facilities allow, vulnerability to chemical and biological attacks should be minimized. NIST might do this work with universities and the national laboratories.
Recommendation 8.23: Analytical studies, like those performed for earthquake hazard assessments, should be conducted to evaluate the effects of explosions and aircraft impacts on covered stadiums. Each major stadium (and its roof system) in the country should be analyzed.
Recommendation 8.24: Conduct analyses of how different toxins might be distributed, controlled, or filtered by the air-handling and circulation systems of stadiums, as well as of other places where large public gatherings occur, and make the resulting information widely available, particularly for commercial purposes.
Once there is evidence of an attack, adequate provisions for egress must be available. Unfortunately, the egress built into stadiums and similar facilities currently in use do not consider any kind of terrorist attack or the panicked exodus of a large crowd. But crowd management can be improved by physical or structural amenities and by training and preparation. Improved exits, modified barriers that mitigate injuries, signage, and other modifications to the existing requirements for moving people out of crowded and enclosed spaces should be available to local authorities. Such improvements can also have salutary effects on attendees’ attitudes—and on their behavior in the event of a crisis. For example, the highly publicized security at the 2002 Super Bowl reassured attendees, so that even if there had been an incident, attendees would probably not have acted irrationally. As noted in Chapter 9, psychology and social science resources can be brought to bear on efforts to develop more effective methods of crowd management.
We must be able to monitor the air circulating in stadiums for dangerous toxins, but reasonable means are not available for detection of the wide variety of potential chemical and biological agents. Therefore sensors to detect toxins,