Unusual Weather Damage
Even on the periphery of a tornado, or in one of its weaker phases, flying debris remains a major danger. A night tornado on 26 April 1991 launched a chunk of unknown debris ("missile" in damage survey parlance) through the brick veneer of the Oologah (OK) High School gym. Gymnasiums are inherently unsafe in a tornado anyway because of weak support for large-span roofs; but this illustrates an extra danger that is present anywhere near an outer building wall. The tornado approached from left rear (SW) and blew out only the large, relatively weak loading doors and an enclosure at rear -- each made of flimsy sheet metal. Elsewhere, parts of the roof were removed. Although the tornado did up to F4 damage on other places, the damage at the school was no more than low-end F1.
Oologah OK (17 May 91) looking NW