A range of studies has indicated that the dynamic linkages between community fabric and disorder levels is such that declining economic status and increasing non-white populations were associated with increasing delinquency. This ecological orientation has as its methodological corollaries the consideration of overall neighborhood structure and the neighborhood's relative position in the urban ecology. There are also several theoretical corollaries: historical context determines the kind of forces for change likely to operate in a neighborhood during a period of time; different types of neighborhoods will change differently; and faster, more extreme change is associated with more violence. The two ecological forces dominant in Baltimore were the worsening of the underclass and neighborhood gentrification. The more radically their roles in the overall fabric of city life were changed, the more violent they became in comparison to other areas. Urban officials can predict neighborhoods most at risk of swift ecological change during the present decade, monitor changes using real estate and tax information, and concentrate service delivery on those neighborhoods experiencing the greatest shifts in status and stability. 1 figure, 19 references. (Author abstract modified)