School hallways may not be the best place to ride out tornados, despite a long-standing tradition of ducking and covering along corridors.
That's one of the lessons emergency managers have learned from recent devastating tornadoes, particularly the Moore tornado that hit this Oklahoma City suburb on May 20, 2013. Seven children died at Plaza Towers Elementary School when the EF5 tornado hit, tearing away the roof and collapsing hallway walls onto huddled students. The damage highlighted the unfortunate fact that many schools are simply not built for safety.
"I have walked through schools and left thinking, 'Please don't let a storm come anywhere near this building,'" said Andrea Melvin, the outreach programs coordinator for Oklahoma Climatological Survey and Oklahoma Mesonet. Few school architects consider weather safety in their designs, she told Live Science. [Photos: Aftermath of the Moore Tornado]
"School designs need to change," she said "We cannot continue to add more glass everywhere and expect to have safe areas for sheltering. We can’t build walls that are not connected to the roof and foundation."
Melvin and her colleagues, who presented findings about school readiness at the American Meteorological Society meeting in Atlanta on Feb. 3, are fighting to better prepare Oklahoma schools for severe weather. There are an average of 47 tornadoes in the state each year, according to the National Oceanic and Atmospheric Administration (NOAA), and the whirlwinds cause an average of three deaths each year.
Despite this danger, building codes are not designed to ensure that schools withstand the kinds of winds even the most modest tornado can muster. The standard is to build schools to resist 90-mph (145 km/h), straight-line winds. The weakest EF1 tornadoes can sustain gusts of up to 110 mph (177 km/h), and their rotational winds put more pressure on buildings than a straight-line wind of the same speed, Iowa State University engineer Partha Sarkar told Live Science in 2013.
"The buildings are simply not designed to withstand that level of wind," Sarkar said.
The Moore tornadoes have prompted changes to the codes. In March, Moore adopted codes requiring that all new homes stand up to 135-mph (217 km/h) winds. And an International Building Code update that goes into effect in 2015 will require safe rooms in schools in the regions around Moore. Those regions are prone to strong tornadoes, and the safe rooms in the area should be built to stand up to 250-mph (402 km/h) winds.
But existing schools have particular vulnerabilities. In urban areas, the schools are frequently under construction, because of expanding student populations, Melvin and her colleagues reported. Many rely on "portable classrooms," which are simply metal storage units that provide no shelter against strong winds. Building walls may consist of cinderblocks stacked upon each other with nothing reinforcing them, Melvin told Live Science. Requests for bonds to raise money for improvements must be placed before voters, who frequently vote down these initiatives.
Meanwhile, the architecture of many schools makes finding shelter difficult. Hallways are often on the exterior of the building, lined with glass windows. Schools built during the period when open floor plans were popular are often retrofitted with walls made of unreinforced sheet rock, which simply collapse once the roof is breached.
Even interior hallways can be dangerous if they have doors on either side. During the Joplin, Missouri, tornado of May 22, 2011, school hallways turned into wind tunnels, with huge chunks of debris blowing freely through Joplin High School and East Middle School. Fortunately, the tornado hit on a Sunday, so students were not present.
Keeping students safe
In the wake of the Moore tornado, the Oklahoma Department of Emergency Management has started a program called Safe Schools 101, which trains volunteer architects, engineers and emergency officials how to evaluate the safety of school structures. The first classes started in early 2014, and the eventual goal is to evaluate every school in the state.
In the meantime, Melvin said that school officials should take a hard look at their school's emergency plans. The safest shelters are interior rooms with strong connections between foundation, walls and roof — and no windows. Bathrooms and locker rooms can be good options, though basements may not be best due to water or gas lines.
Some schools — including the two being rebuilt in Moore — are equipped with safe rooms, and parents are increasingly pressuring school districts to provide these rooms for every student. Teachers surveyed by Melvin and her colleagues unanimously agreed that every school should have a safe room. Such an initiative would cost more than $2 billion, however, Melvin said. [Tornado Safety: Where to Go & What to Do]
Nevertheless, safe rooms can be the difference between life and death. A poster presented at the AMS meeting by the researchers quoted a teacher who did have access to one of these rooms.
"As a teacher taking shelter in an all-school safe room while the May 20, 2013, EF-5 tornado passed about a mile away, I felt safe and reassured that my students were not at risk, but also felt panicked and helpless knowing that my own children's lives and thousands of other students' lives were not protected as they huddled in bathrooms and under desks at their nearby schools," the teacher said.
Another teacher, who was sheltering in the hallway at Plaza Towers Elementary, where seven students died, described her experience in that school's hallway.
"We heard the roar coming closer and closer, and realization sunk into my mind that it was upon us," she said of the tornado. "The kids were screaming then. We were all praying. I had my arms around a fourth-grade boy who was screaming over and over, I want my momma, I want my momma. I told him I would be his momma for now and that I wouldn't let go of him."