National standards should be set for building construction, storm shelters and emergency communications to reduce death and damage from tornadoes, a federal agency that studied the deadly 2011 tornado in Joplin, Mo., recommended on Thursday.
The National Institute of Standards and Technology (NIST) said 135 of the 161 deaths from the May 22, 2011 tornado resulted from building failure. The EF-5 tornado was the deadliest single tornado in the United States since official records were first kept in 1950, according to the agency.
The study was the most detailed ever conducted after a tornado, the agency said, and comes in the wake of Midwest tornadoes early this week that caused $1 billion in damage and killed six people in Illinois and two in Michigan.
The Joplin tornado damaged more than 8,000 homes and other buildings. People died in commercial, retail and residential structures due to lack of emergency shelters and basements. About 82 percent of Joplin homes do not have basements because of soil conditions.
“The time is right to develop and implement codes and standards that better protect our citizens and help communities recover more quickly from these powerful, but not invincible, natural forces,” Eric Letvin, director of disaster and failure studies at NIST, said at a press conference in Joplin.
The report recommended 16 changes in codes and regulations. To a varying degree, each would need to be approved by federal, state or local entities, Letvin said.
Current U.S model building codes protect against hurricanes, floods and earthquakes but not the extreme wind speeds of tornadoes, except at nuclear power plants and tornado shelters, Letvin said.
The basic minimum residential building code in the United States is agreed through the International Code Council, a body that brings together homebuilders, architects, engineers and government officials to update rules every three years.
Letvin said the NIST would work with experts to craft stronger standards. State and local governments across the nation would be involved, he said.
The city of Joplin made some changes in its residential building code after the tornado, such as requiring more roof and foundation fasteners. But more extensive changes met opposition due to high cost, City Manager Mark Rohr said Thursday.
National standards could create the same concerns and require a lot of local review, Rohr said.
“It’s clear they are using this report to advance ideas that would have an impact on the national level, but the devil is in the details,” Rohr said. “I’m a proponent of local government and to determine policy on a local level.”
Letvin estimated that upgrading construction to make buildings more resistant to tornado damage would add 5-15 percent to the cost of a new home and more for a commercial structure.
But the added cost has to be weighed against the $2 billion in insured damage Joplin suffered from the tornado, he said.
The NIST also recommended tornado shelters be put in new and existing multifamily residential complexes, schools, theaters, churches and other places where more than 50 people might be at one time.
“Our report is fact-finding, not fault-finding,” Letvin said.