WASHINGTON, D.C. — In towns ravaged by a deadly tornado outbreak earlier this month, the clean-up is painstaking and painful.
"They don't have anything. No belongings left," said Taylor Powell, a resident of Marshall County, Kentucky. "It's just gone."
It's a task made harder by the complete destruction of so many homes and buildings.
"I'm not sure what we're saving is going to be even worthy for us to use, but we're trying our best to hold on to what we have," said Mayfield, Kentucky resident Robin Campbell.
Marc Levitan is the lead research engineer for the National Wind Impact Reduction Program, which is part of the National Institutes of Standards and Technology.
"It's still quite shocking, especially this time of year," he said.
Just days before the tornadoes struck Kentucky and five other states, Levitan and other researchers, along with the American Society of Civil Engineers, released new guidance for building codes in tornado zones.
"We now, for the first time, have a methodology and procedures to calculate tornado loads on buildings," Levitan said.
It focuses on critical structures, like schools, hospitals and emergency services.
"They provide information to the designers for what would be the loads that the building has to resist, and then the engineer and the building design team would take those loads and select the appropriate wood framing, steel, concrete — whatever materials are being used for that building," Levitan said.
The guidance builds on research from previous major tornadoes, like the tornado that struck Joplin, Missouri, in 2011.
However, unlike building codes adopted for hurricanes, as Florida did in 1992 after Hurricane Andrew, building codes for tornadoes haven't quite caught up.
"We're a couple of decades behind in just our scientific understanding of tornadoes, of tornado frequency of occurrence, of tornado hazards," Levitan said.
The next step is to get the new guidance into official building codes that local and state governments can adopt.
"Right now, the building codes and standards — with the exception of tornado shelters — the word 'tornado' doesn't appear in our building codes and standards," Levitan said. "So, we shouldn't be surprised that we have poor performance of buildings in tornadoes because we don't design for them."
It's something officials hope to change so that the losses seen recently from the deadly tornado outbreak don't happen again.