"...any kind of planning has to be realistic. It has to be built upon real knowledge... not stem from theoretical speculations but studies of actual disasters. Disaster planning has to be realistic also in that it cannot presuppose an ideal situation but the probable situation.... good disaster plans are developed so that they can be adjusted to people rather than attempting to force people to conform to planning. Finally, disaster planning has to be realistic in the sense that it is taken for granted that planning can be undertaken. Persons with vivid imagination can always come up with hypothetical possibilities so horrendous that they serve to immobilize any effort at planning... It is far more realistic to assume probable situations because that is what is likely to occur and for which community planning can be undertaken". (Dynes, et al., A Perspective on Disaster Planning, 1981, p. iv)