Although the hurricane Katrina is not the greatest natural disaster that has struck the US, there is no doubt that it was without a precedent among recent natural disasters. Disaster consequences mostly depend on society development, as well as on its ability to absorb disasters and provide disaster relief. As this case seems to involve a rich country with highly developed disaster management system, an effective response was naturally expected. Why did Katrina happen at all? Katrina can be regarded as an example of how one particular disaster turns into another, of much greater proportions. Therefore, the main thesis of this paper is that Katrina embraces three disasters: natural, technological and social. In addition, three factors causing a disaster are given: physical vulnerability, social vulnerability, and disaster response. Furthermore, the focus is on city abandoning and an increase in crime and violence being the main aspects of social disaster during and in Katrina’ s wake. Accordingly, Katrina seems to be the “ worst case” although an optional explanation is given as well. In conclusion Katrina is considered in social, community and civilizational terms.