There is perhaps no crueler irony during a natural disaster than when the destruction comes to a haven for the injured. That’s what happened on May 20, when an EF-5 tornado tore through Moore, Oklahoma and destroyed its relatively new 45-bed hospital. Sixteen minutes after cable programs were interrupted and outdoor sirens started blaring, the twister cut a 17-mile path that killed 24 people, shredded two elementary schools and reduced many homes to matchsticks. Last night, the region faced yet another onslaught of twisters.
A hospital spokeswoman confirmed to TIME that Moore Medical Center was unsalvageable and would be demolished as plans for a potential replacement evolve over the next six months. However they shake out, officials there and throughout Tornado Alley — the swath of midwestern heartland that sees the brunt of the country’s cyclones this time of year — could learn a lot from St. John’s Regional Medical Center in Joplin, Missouri.
Two years ago, St. John’s was directly hit by a EF-5 tornado. Staff and patients couldn’t find safety, the roof blew off and the backup generator failed, plunging the facility into darkness and leaving most life-saving equipment useless. Of the 161 people who died in that storm, six were in the hospital. “I never would have believed it would have done that much damage without seeing it with my own eyes,” says John Farnen, director of strategic projects, who’s coordinating the planning and construction of the new hospital. “The first two days, we were in awe and disbelief of what we saw.”
(MORE: Fresh round of tornadoes rattle Oklahoma City)
When St. John’s reopens in March 2015 as Mercy Hospital Joplin, however, it will be a paragon of virtually tornado-proof construction. As part of the rebuilding effort, which began in January 2012, each hospital floor will have a windowless safe zone, where everyone can seek shelter; electrical wiring will be buried underground to prevent power failure; and a waterproof “membrane” and concrete slab will be installed beneath the roof, designed to stay put even if the outermost layer peels off.
But it’s the window armor that’s most impressive. In Joplin, as in Moore, most of the hospital’s glass gave out after being impacted by 200 mph gusts and debris. To avoid a repeat tragedy, Farnen’s team wanted to ensure that the new facility’s windows could withstand those threats — and then some. Problem was, they didn’t exist.
So they commissioned Architectural Wall Systems, a Des Moines-based design and manufacturing house, to custom-make an entirely new type of window. Thicker-than-average glass is layered with an extra protective glazing and framed into an aluminum curtain wall that’s fastened to the building in more ways than a standard window, allowing it to better absorb the shock of a blow.
(COVER STORY: 16 Minutes)
In testing, technicians blasted them — twice, using an air cannon — with wooden two-by-fours, traveling at high speeds. Then, they were subjected to a pressure chamber that mimicked the give and pull of a tornado. The windows cracked but didn’t break apart and collapse, much like car windshields. They were also able to “flex” up to three inches and remain in their casing without allowing air to pass.
The windows that passed testing can withstand wind speeds of 140 mph or 250 mph, respectively, meeting international standards for high winds or storm shelters. The strongest will be placed in the most sensitive areas, like intensive care units, where patients on life support can’t be moved quickly. The rest of the hospital will be outfitted with the same type of pane that survived the May 2011 tornado, which met the commercial 90 mph threshold but was hardened with a layer of protective glazing.
But that safety comes at a price. The 250 mph window costs $170 per square-foot, or $30 more than the 140 mph unit and $70 above the base. All together, approximately 59,000 square feet of windows for Mercy Hospital Joplin will cost about $6.45 million. That’s a lot when compared with, say, the $70,000 spent on laminated safety glass at another hospital in Tornado Alley. But when factored into the $450 million reconstruction of Joplin’s hospital—the only facility approved for the 250 mph unit so far—it’s just 1.43% of the budget.
(MORE: Moments of Hope in Oklahoma: One Photographer’s Story)
For Moore, justifying that expense must be weighed against the perceived threat. If the windows are retrofitted into a poorly structured existing building, the cost is higher and that money could be wasted when winds pick up. But if they’re built into a new one alongside other weatherproofing materials, they’re stronger and the tab’s lower.
But even if a building is expertly engineered, thought-out construction can’t be the sole defense. Safety procedures matter, too. “The people who work in the building have to make use of the protection that the building offers,” says John Snow, a meteorology professor at the University of Oklahoma. “I personally would not stand in front of those windows, looking out into 200-mph windows throwing two-by-fours at me.”
Few would. But in Joplin, where thousands of homes and more than 500 businesses were wind-axed, it’s just one of many welcome advancements. Bill Scearce, the town’s vice-mayor, says 84% of tornado-damaged homes have been (or are scheduled to be) fixed or rebuilt, and most businesses have reopened. And he’s confident Moore will see similar progress. “Every day will be better than the day before,” he says. “We recovered. They will recover. It will be a lasting memory.”