One of the replacement schools was a supermarket that had been empty for 10 years. Another structural conversion reconfigured a warehouse. The team selected materials based on availability and delivery time. It took just minutes for a tornado packing 200-mph winds to level a third of Joplin, Mo.'s public schools last spring. In a remarkable turnaround, it took less than three months to bring the schools back on line in time for the new school year. On Aug. 17, classroom sessions resumed on schedule in Joplin, even as construction crews continued cleaning up from the May 22 tornado, an EF5