The tornado that hit Joplin, Missouri on May 22, 2011 caused 161 fatalities and $1.228 billion dollars in commercial property losses, according to the Joplin city government. In an effort to reduce the death and destruction caused by natural disasters, the U.S. Commerce Department's National Institute of Standards and Technology (NIST) completed a technical investigation of the Joplin tornado. The culmination of the findings were released in a report along with recommendations to better safeguard tornado-prone communities.
The NIST study is the first to scientifically assess the impact of a tornado in four major categories: tornado characteristics, building performance, human behavior, and emergency communication—and the impact of each on life-safety. It also is the first to recommend that standards and model codes be developed and adopted for designing buildings to better resist tornadoes.
Following the public comment period, NIST will issue a final report and then work with the appropriate code development organizations to use the study's recommendations to improve model building codes and lay the foundation for nationally accepted standards. NIST also will work with organizations representing state and local governments—including building officials—to encourage them to seriously consider implementing its recommendations.
"The overarching conclusion of our two-year study is that death and destruction from tornadoes can be reduced," said Eric Letvin, director of disaster and failure studies for NIST. "It's time to begin developing and implementing standards and codes that directly address tornado hazards."
In the majority of cases, the study found that regardless of construction type, buildings did not adequately protect occupants and that Joplin residents had limited access to underground or tornado-resistant shelters. The majority of deaths (135 or 83.8%) were caused by impacts associated with building failure. Virtually all of the buildings in which people died were affected by wind speeds equivalent to an EF-3 tornado or higher on the Enhanced Fujita scale.
Based on findings from the investigation, NIST developed 16 recommendations for improving how buildings and shelters are designed, constructed, and maintained in tornado-prone regions; and for improving the emergency communications that warn of imminent threat from tornadoes.
The key recommendation proposed in the report is "the development and adoption of nationally accepted performance-based standards for the tornado-resistant design of buildings and infrastructure to ensure the resiliency of communities to tornado hazards." This includes a call for designing and constructing essential buildings—such as hospitals and emergency operations centers—and infrastructure to remain operational in the event of a tornado.
The report also recommends uniform national guidelines be developed that enable communities to create the safest and most effective public sheltering strategies. Shelters, the report states, should be installed in new and existing multi-family residential and commercial buildings, schools, and in buildings with assembly occupancies located in tornado hazard areas.
The full draft report can be found on the NIST website.