The purpose of this study is to find the optimal locations of fire fighting facilities in Incheon to prevent the spread of accidental fires and efficiently extinguish them. In the event of a large fire difficult to cope with in one fire fighting facility, additional support from nearby facilities will be necessary. The model proposed in this study firstly ensures that all demand nodes in a network will be able to be reached from the minimum number of facilities in a given time. At the same time, we locate the given number of facilities so that they can cover as many demand nodes as possible multiple times. This problem can be considered as a facility location problem which aims at maximizing the number of demand nodes that are covered at least twice while minimizing the number of facilities needed. The proposed model is applied to conduct a case study using road network information and administrative district data in Incheon.