From Colorado and Connecticut to Florida and Texas, school shootings have struck the U.S. education system. In response, there has been a proliferation of policies, programs, and practices to make schools safer. We term this phenomenon the fortification of schools. Fortification entails prioritizing and instituting various structures, resources, and routines that militarize schools; defines "safety" as a function of the school building; and positions educators as responders to gun violence. Thus, fortification asks educational administrators, teachers, and staff to work in new ways. To expose and better understand the policies, resources, and practices associated with fortification, we apply theories of structuration and racialized organizations. In so doing, we illuminate how fortification is continually shaped by systemic racism. Our discussion of fortification explains racialized dimensions of school safety policy implementation, operationalizes facets of structure-agency theory, and provides recommendations for practitioners and scholars concerned with responses to school shootings.