NIST World Trade Center Investigation Team Calls for Improvements

Draft Report and Recommendations on Safety, Emergency Response Released for Comment

June 23, 2005 – NEW YORK – The U.S. Commerce Department’s National Institute of Standards and Technology (NIST) today called on the organizations that develop building and fire safety codes, standards and practices�and the state and local agencies that adopt them�to make specific changes to improve the safety of tall buildings, their occupants and first responders. The recommendations result from the agency’�s investigation of the fires and collapses of New York City’s World Trade Center (WTC) towers following the terrorist attacks of Sept. 11, 2001.

Based on the findings of the most detailed examination of a building failure ever conducted, NIST is making 30 recommendations. �We believe these recommendations are both realistic and achievable within a reasonable period of time, and should greatly improve the way people design, construct, maintain and use buildings, especially high-rises,� said WTC Lead Investigator Shyam Sunder at a press briefing in New York City. �The recommendations also should lead to safer and more effective building evacuations and emergency responses. However, improvements will only be realized if they are acted upon by the appropriate organizations.”

The recommendations, contained within 43 draft reports (totaling some 10,000 pages) released today for a six-week public comment period, cover:

  • specific improvements to building standards, codes and practices;

  • changes to, or the establishment of, evacuation and emergency response procedures; and

  • research and other appropriate actions needed to help prevent future building failures.

The recommendations (see the NIST WTC Web site at for the complete list) are divided into eight groups:

  • Increased Structural Integrity: The standards for estimating the load effects of potential hazards (e.g., progressive collapse, wind) and the design of structural systems to mitigate the effects of those hazards should be improved to enhance structural integrity.

    Among the recommendations in this group are:

    • nationwide adoption of standards and codes to prevent progressive collapse;

    • more reliable means of predicting failure in structures subjected to multiple hazards; and

    • nationally accepted standards for wind tunnel testing of prototype structures and estimating wind loads for tall buildings.

  • Enhanced Fire Resistance of Structures: The procedures and practices used to ensure the fire resistance of structures should be enhanced by improving the technical basis for construction classifications and fire resistance ratings; improving the technical basis for standard fire resistance testing methods; using the �structural frame� approach to fire resistance ratings; and developing in-service performance requirements and conformance criteria for spray-applied fire resistive materials (SFRMs, commonly referred to as �fireproofing� or �insulation�).

  • Among the recommendations in this group are:

    • evaluating, and where needed, improving the technical basis for determining appropriate construction classifications and fire rating requirements�especially for buildings greater than 20 stories in height�and making related code changes now by considering a variety of factors (including timely access by emergency responders, full evacuation of occupants and redundancy in fire protection systems critical to structural safety);

    • improving the century-old standard for fire resistance testing of building components, assemblies and systems; and

    • developing and implementing criteria, test methods and standards for measuring the in-service performance and as-installed condition of “fireproofing.”

  • New Methods for Fire Resistance Design of Structures: The procedures and practices used in the design of structures for fire resistance should be enhanced by requiring an objective that uncontrolled fires result in burnout without local or global collapse. Performance-based methods are an alternative to prescriptive design methods. This effort should include: (1) the development and evaluation of new fire resistive coating materials and technologies, and (2) the evaluation of the fire performance of conventional and high-performance structural materials (such as fire-resistant steels and concretes). Technical and standards barriers to the introduction of new materials and technologies should be eliminated.

  • Active Fire Protection: Active fire protection systems (i.e., sprinklers, standpipes/hoses, fire alarms and smoke management systems) should be enhanced through improvements to design, performance, reliability and redundancy of such systems.

  • Among the recommendations in this group are:

    • enhanced fire protection systems that provide redundancy and accommodate greater risks associated with increasing building height and population, more open spaces and higher threat profiles of particular buildings;

    • fire alarms and communications systems that provide continuous, reliable and accurate information on life safety conditions; and

    • real-time secure transmission of data from fire alarm and other monitored building systems for use by emergency responders at any location, and presentation of that information either off-site or in a black box that that can survive a fire or other building failure.

  • Improved Building Evacuation: The process of evacuating a building should be improved to include system designs that facilitate safe and rapid egress; methods for ensuring clear and timely emergency communications to occupants; better occupant preparedness for evacuation during emergencies; and incorporation of appropriate egress technologies.

  • Among the recommendations in this group are:

    • improving occupant preparedness for building evacuations through joint and nationwide public educational campaigns;

    • designing tall buildings to accommodate full building evacuation of occupants if needed�including stairwell and exit capacity that accommodates counterflow due to access by emergency responders;

    • maximizing the remoteness of egress components (i.e. stairs, elevators) without making them hard to reach;

    • using pagers and cell phones for broadcast warning systems and Community Emergency Alert Networks; and

    • evaluating for future use such advanced evacuation technologies as protected/hardened elevators, exterior escape systems and stairwell navigation devices.

  • Improved Emergency Response: Technologies and procedures for emergency response should be improved to enable better access to buildings, response operations, emergency communications, and command and control in large-scale emergencies.

    • Among the recommendations in this group are:

      installing fire-protected and structurally hardened elevators to improve emergency response activities in tall buildings;

    • installing, inspecting and testing emergency communications systems to ensure that the systems and their protocols will function in challenging radio frequency propagation environments and can be used to track emergency responders within a building; and

    • developing and implementing protocols for ensuring effective and uninterrupted operation of the command and control system in large-scale building emergencies.

  • Improved Procedures and Practices: The procedures and practices used in the design, construction, maintenance, and operation of buildings should be improved to include encouraging code compliance by nongovernmental and quasi-governmental entities; adoption and application of egress and sprinkler requirements in codes for existing buildings; and retention and availability of building documents over the life of a building.

  • Education and Training: The professional skills of building and fire safety professionals should be upgraded through a national education and training effort for fire protection engineers, structural engineers and architects.

NIST strongly urges that immediate and serious consideration be given to these recommendations by the building and fire safety communities�especially designers, owners, developers, codes and standards development organizations, regulators, fire safety professionals, and emergency responders. NIST also strongly urges building owners and public officials to (1) evaluate the safety implications of these recommendations to their existing inventory of buildings; and (2) take the steps necessary to mitigate any unwarranted risks without waiting for changes to occur in codes, standards and practices. NIST further urges state and local agencies to rigorously enforce building codes and standards since such enforcement is critical to ensure the expected level of safety.

NIST is assigning top priority to work vigorously with these communities to ensure that there is a complete understanding of the recommendations and their technical basis and to provide needed technical assistance for their implementation. As part of this effort, NIST will develop and maintain a web-based system with information on the status of NIST�s recommendations that will be available to the public so that progress in implementing them can be tracked.

In addition, NIST will hold a conference on Sept. 13�15, 2005, at its headquarters in Gaithersburg, Md., to reinforce the importance of its findings and recommendations from the investigation and encourage their implementation. Details on this conference and registration information are available at