Objective: An accidental fire that occurred in a hillside residential area in the city of Nagasaki was evaluated to assess the challenges faced by communities located on sloped terrains and to develop community-based support systems applicable to such hillside residential areas.Methods: Community observations and key-informant interviews were performed in the area affected by the fire. A self-administered questionnaire survey was also conducted among residents of the affected area. Information obtained through community observations of the fire-struck area and key-informant interviews was analyzed and assessed using a two-dimensional (2D) framework.Results: According to community observations and key-informant interviews, initial firefighting efforts were delayed due to lack of preparedness, in addition to geographic factors such as narrow roads and outdoor staircases, which allowed the fire to spread. The livelihood and health support measures for elderly residents requiring evacuation assistance were also insufficient. A hospital neighboring the area affected by the fire accident voluntarily provided some services to evacuees, but support from other nearby organizations/institutions was either not available or not offered. According to the questionnaire answers, elderly residents had little knowledge of the location and proper use of fire hydrants in their area. In addition, 65% of the respondents had never participated in disaster training exercises. From these results, the following three points could be determined: 1) The geographic features of the hillside residential area enhanced the spread of the fire. 2) The multi-sector support systems for evacuees were inadequate, collaboration among the existing systems was insufficient, and the roles of those systems were not fully clarified in advance. 3) Elderly residents in the hillside residential area did not have sufficient the knowledge and/or ability to engage in fire prevention activities and had inadequate firefighting skills.Conclusions: It is important to improve disaster preparedness knowledge and training for local residents on ordinary times. Additionally, cross-sector collaborative disaster response, harmonious management, and support systems must be ensured and sustained before, during, and after disasters.