In the hazard map of Ishinomaki city, distributed to citizens before the Great East Japan Earthquake, it was predicted and shown there may be a 3.5 km tsunami run up from the river mouth to the alluvial plain along Kitakamigawa River. Okawa Elementary School, seriously affected in the earthquake, was located only 0.5 km upstream from the predicted inundation area. Taking into consideration the diversity of tsunami mechanism and tide, 0.5 km in the plain area can be considered as a "margin of error". In the hazard map, there was also a note about an earthquake that could trigger an enormous tsunami in comparison to the seismic intensity felt by people. In other words, the occurrence of a magnitude 8 quake had been officially foreseen in the case of Miyagi-ken-oki Earthquake, so it is not possible to say the inundation at Okawa Elementary School, provoked by the tsunami, was an unexpected one.
Although emphasis has been given on the importance of evacuation drill and creation of manual, disasters may not occur as anticipated. Approaches will be made about man-made disasters in natural catastrophes for not taking into consideration Geoscience knowledge, as in the case of the predictable unexpected calamity at Okawa Elementary School.