Following in the wake of great disasters which descend from time to time upon our cities, paralyzing the public services that make crowded city conditions possible, is the outcropping of disease that may, if unchecked, prove more disastrous even than the catastrophe itself. This tendency was discernible in the first reports of the floods that have recently devastated Ohio, Indiana and adjoining states, due to the heavy rains of March 24–28. Nearly every flooded city reported that its water works plant had been put out of commission, or the water supply polluted, which with the increased chance of infection, and the general lowering of vitality presented a situation of unusual menace and one demanding complete and immediate handling. The most serious situation is Dayton, for here every sanitary problem presented at any other point was involved. The complete, immediate and effective organization to handle the situation which was formed there was typical of the effective work now done at such emergency periods. At Dayton the water works plant was incapacitated by water that reached ten feet above the boiler grates; there was unknown damage to water distribution and sanitary sewerage and drainage systems; storm sewers and catch basins were clogged with filth and debris; dead animals were strewn on every side; the population was at high nervous tension, their vitality lowered by shock, exposure, cold, and lack of food and drink; hundreds of people were crowded for days in single buildings or dwellings; thousands, probably, had been exposed to intestinal infection by drinking the dirty flood water as it swirled through the streets; hundreds had only wet cellars and rooms to return to, if their homes were not altogether destroyed; and everywhere on everything—walls, ceilings, floors, furniture, streets and sidewalks—was a thick coating of the black, sticky, slimy mud left by the retreating waters. This in a measure pictures the situation at Dayton as the flood waters receded. And Dayton knew at once that the toll of the flood would be as nothing compared to the pestilence, unless attention and energy were directed to these problems. This appreciation of the paramount importance of sanitation was a striking revelation of the success of the campaign of sanitary education that has characterized the last century. In every phase of the work of recovery, in the warning signs and directions on almost every post, in the placards on the automobiles of the sanitary department stating that “This car must not be stopped or delayed day or night,” in the daily exhortations in the free newspapers distributed throughout the city, in a thousand ways, Dayton declared again and again: “Sanitation first and foremost. Then everything else.”