Safety Report Drawn from WTC’s Collapse

A federal agency that investigated the fires and collapsing of the World Trade Center’s twin towers following the Sept. 11, 2001, terrorist attack has recommended changes in building standards, fire codes and emergency response methods to improve the safety of high-rise buildings.

The U.S. Commerce Department’s National Institute of Standards and Technology 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. NIST does not have authority to require changes in building codes and standards.

The recommendations, contained within 43 draft reports (totaling some 10,000 pages) cover specific improvements to building standards, codes and practices; changes to evacuation and emergency response procedures; and research and other appropriate actions needed to help prevent future building failures.

The recommendations on improving structural integrity call for more reliable means of predicting failure in structures subjected to multiple hazards and nationally accepted standards for wind tunnel testing of prototype structures.

To enhance the fire resistance of structures, NIST recommends improving the construction classifications and fire ratings-especially for buildings greater than 20 stories high-and making related code changes now by considering timely access by emergency responders, full evacuation of occupants and redundancy in fire protection systems.

Active fire protection recommendations include enhanced fire protection systems and real-time secure transmission of data from fire alarm systems for use by emergency responders at any location.

Building evacuation could be improved, according to the report, if tall buildings were designed to accommodate full building evacuation of occupants, including having stairwell and exit capacity that accommodates both occupants and incoming emergency responders.

The agency also urges consideration for future use of protected or hardened elevators, exterior escape systems and stairwell navigation devices.

“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 New York City press briefing.

“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.”