War authors Zubok and Pleshakov. In U.S. Army training, soldiers are taught to fall down immediately and cover their face and hands in much the same way as is described above. In the classroom scene of the film, the rapid employment of school desks, as an improvised shelter following the awareness of the initial light flash, is a countermeasure primarily to offer protection from potential ballistic window glass lacerations when the slower moving blast wave arrived. However, in higher blast pressure zones, where partial-to-total building collapse may occur, it would also serve a similar role to that borne out from experience in urban search and rescue, where voids under the debris of collapsed buildings are common places for survivors to be found. More rigid examples of void-forming-tables to shelter under include the "Morrison indoor shelter", which was widely distributed by the millions in Britain as a protective measure against building collapse, brought about by blast pressures generated during the conventional bombing of cities in World War II. When warning is given Under the conditions where some warning is given, one is advised to find the nearest bomb shelter, or if one could not be found, any well-built building to stay and shelter in place. Sheltering is, as depicted in the film, also the final phase of the "duck and cover" countermeasure in the surprise attack scenario. Cursory analysis The "duck and cover" countermeasure could save thousands. This is because people, being naturally inquisitive, would instead run to windows to try to locate the source of the immensely bright flash generated at the instant of the explosion. During this time, unbeknownst to them, the slower moving blast wave, would be rapidly advancing toward their position, only to arrive and cause the window glass to implode, shredding onlookers. In the testimony of Dr. Hiroshi Sawachika, although he was sufficiently far away from the Hiroshima bomb himself and was not behind a pane of window glass when the blast wave arrived, those in his company who were had serious blast injury wounds, with broken glass and pieces of wood stuck into them. During earthquakes and tornadoes Similar advice to "duck and cover" is given in many situations where structural destabilization or flying debris may be expected, such as during an earthquake or tornado. At a sufficient distance from a nuclear explosion, the blast wave produces similar results to these natural phenomena, so similar