An important role of post-earthquake emergency management is to minimize the restoration time, which is the sum of the travel time and the response time. The travel time is the time needed to reach the affected area from the dispatch location, while the response time is the time required to bring the situation under control after reaching the affected area. A number of built environment variables, e.g., building collapse probability, and natural variables, e.g., flooding probability, are known to affect the restoration time. Data from St. Louis, Missouri, USA are used in conjunction with a discrete-event-based simulation model to identify the statistically significant variables via an analysis of variance. The experimental results show that in order to reduce the loss of life, the volume of resources and the building collapse and flooding probabilities are significant factors that should be accounted for in the emergency-response planning for an earthquake.