At-Risk People's Safety in Fire Incidents: Insights Learned from Applying Reliability Index Method.

Escaping from a fire to a safe place can take longer and be more difficult for people belonging to at-risk groups. While there are several models addressing uncertainty during evacuation, the effect of these on the elderly and people with disabilities, especially those people who are living alone is seldom exemplified. Considering a common type of detached two-story building with a prevalent layout, this paper illustrates how safety analysis can be developed for these groups based on the fire safety index method. The computations illustrate the probability of being trapped in fire (fatality) and safety index (beta index). The timeline evacuation model for two fire scenarios considers appropriate probability distribution functions for each variable with indeterministic nature. Sensitivity analysis of the variables has been done to find the most important and effective parameters for fire safety for the chosen at-risk groups. The response time to the fire, the area of buildings, and the length of escape route are the most important variables. Also, fire growth is more critical in homes without detection systems. The type of movement disability that needs different kinds of assistive tools, has no great effect on the safety level of people that live in the same home layout and people with visual impairment who need care staff to assist for evacuation encounter the same risk of fatality as other people with movement disabilities approximately.