1 Human Behavior and Fire How one reacts during a fire is related to the role assumed, previous experience, education, and personality; the perceived threat

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Human Behavior and Fire

How one reacts during a fire is related to the role assumed, previous experience, education, and personality; the perceived threat of the fire situation; the physical characteristics and means of egress available within the structure; and the actions of others who are sharing the experience.

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•In theUnited States, during the 1940s and the 1950s, there was a lack of interest in studies on human behavior in fires. Even in fires that resulted in large loss of life, such as the Cocoanut Grove fire, dedicated human behavior studies of the responses of occupants were not conducted.


•The most productive period for research and publications in the United States on human behavior appeared to be from 1970 through the mid-1980s. The 5 year study and report of the National Commission on Fire Prevention and Control in 1973, entitled America Burning, provided a federal government focus on the national fire problem.


•The emphasis of the studies during this period was on defining human behavior in fire situations,including the examination of the then popular concept of “panic behavior” and an emphasis the study of the evacuation process as it occurred in high-rise building fires

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•It must be recognized that an individual’s behavior in a fire is affected by the variables of the building in which the fire occurs and by the appearance of the fire at the time of detection.


•For example, a response will vary if an individual smells smoke rather than sees flames or dark, acrid smoke completely obscuring a corridor.

•Variables of the fire protection provided for the building may also be critical to the individual’s perception of the threat involved. 11

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•In the process of investigating these case studies we have come to believe that the period between detection of the fire and the arrival of the fire department is the most crucial lifesaving period in terms of the first compartment the area in direct contact with the room of origin and the fire.

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AWARENESS OF THE FIRE

•Obviously, the way an individual is alerted to the presence of a fire may determine the degree of threat perceived. With vocal alerting systems in buildings, variations in voice quality, pitch, or volume, as well as the content of the message, tend to provide threat cues. 4-4


•Studies indicated that the development of “informative fire warning systems,” which use a graphic display with a computer-generated message and a high-pitched alerting tone, has reduced the observed delay times in the initiation of practice evacuations.


•The study of the response times of staff personnel to fire alarm signals in Veterans Administration hospitals found the greatest delay in response time with coded alarm bell systems. 4-4

Initial Means of Awareness•Most of the participants in residential

occupancy studies were alerted initially to the fire by the odor of smoke. When the two categories “notified by family” and “notified by others” are combined, however, personal notification becomes the most frequently reported means of initial perception of fire. 4-6

Initial Means of Awareness

•The authors indicate the most frequent initial cue reported by 146 (69%) of the survivors in Tower 1 was building movement, feeling the building sway and tremble.

Initial Means of Awareness•The most frequent initial cue

reported by 96 (66%) of the survivors in Tower 2 was the sight of fire, smoke, and debris from Tower 1. The authors note only 25 survivors (6%) who indicated building alarms in their media accounts. 4-6


•The predominant activity of the survivors in World Trade Center 1 following their awareness of the unusual threatening cues, prior to initiating evacuation, was “Talked to Others,” which would appear to be a “validation” action, as individuals were formulating their “definition” of the event, which was necessary for them to formulate their “evaluation” of a behavioral response. 4-7


•Research literature developed from practice evacuations indicates that the use of verbal directive informative messages may be the most effective way to reduce delay in evacuation initiation.

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•Note that if verbal directive messages conflict with other awareness cues, such as the odor or sight of smoke, occupants may question the credibility of the message and disregard the information.4-6

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•In the study of the survivors’ behavior in the terrorist aircraft attacks on the two World Trade Center towers on September 11, 2001, based on media accounts, indicated that 357 persons mentioned being alerted by the means presented in Table 4.1.5.


•The authors indicate the most frequent initial cue reported by 146 (69%) of the survivors in Tower 1 was building movement, feeling the building sway and tremble.

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•In the study of the survivors’ behavior when the terrorist aircraft attacks on the two World Trade Center towers on September 11, 2001, based on media accounts, indicated that 357 persons mentioned being alerted by the means presented in Table 4.1.5.

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Initial Means of Awareness•The most frequent initial cue

reported by 96 (66%) of the survivors in Tower 2 was the sight of fire, smoke, and debris from Tower 1. The authors note only 25 survivors (6%) who indicated building alarms in their media accounts.

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Initial Means of Awareness•Physical cues of the aircraft striking

the building consisted of 93 percent of the awareness cues to the occupants, as indicated by the following: “building moving, impact, shaking, swaying, boom, crash, explosion, blast, roar, rumbling.”

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•The predominant activity of the survivors in World Trade Center 1 following their awareness of the unusual threatening cues, prior to initiating evacuation, was “Talked to Others,” which would appear to be a “validation” action, as individuals were formulating their “definition” of the event, which was necessary for them to formulate their “evaluation” of a behavioral response.

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Awakening

•A study of the NFPA-recommended smoke detector noise level of 75 dBA indicates that individuals with hearing impairments, those taking sleeping pills, or those on medication may require a detector noise level exceeding 100 dBA28. 4-8

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Awakening•A study of 24 male subjects designed

to determine whether they were awakened by a smoke detector’s audible alarm signal and could identify fire cues found that the subjects slept through the alarm signals at a signal-to-noise ratio of 10 dBA and consistently failed to identify the awakening cue or radiant heat and smoke odor cues as fire warnings.4-8

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Awakening•A signal passing through a ceiling or a

wall may be reduced by 40 dBA, whereas a signal passing through a door may be reduced by 15 dBA; in addition, the signal could be masked by a typical residential air conditioner noise level of 55 dBA. 4-8

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Awakening•Sleep-deprived young adults will not

reliably awaken to an alarm signal. Both the frequency of awakenings and the intensity of a stimulus required to induce awakening are related to age, with more frequent awakenings in response to lower stimulus intensity as age increases. 4-8

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Awakening

•Human voice alarms have distinctive appeal in that they convey meaning and can also directly convey emotional significance.The research has found the following:

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Awakening

•The way in which signal words are spoken determines the believability, appropriateness, and most importantly, sense of urgency being conveyed.

•An increase in pitch of voice is equated with an increase in the perceived intensity of the emotion being conveyed, whether this emotion is positive or negative. 4-8

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Awakening

•Human voice alarms are perceived as more urgent and intelligible, than computer synthesized voice alarms, even when the computer generated sound has been manipulated to convey urgency.

•The female voice is perceived to be more urgent than the male voice. 4-8

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Awakening

•The level of urgency perceived varies for different signal words with “deadly” and “danger” perceived as more urgent followed by “warning,” “caution,” and “note.”4-8

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Ambiguous Threat Cues

•Social inhibition, diffusion of responsibility, and mimicking have been indicated to be primarily responsible for the inhibition of adaptive and assistance behavior in emergencies


•The inhibition of behavior in the early stages of a fire, when the cues are relatively ambiguous, may lead to nonadaptive flight behavior because the time available for evacuation has been expended.4-11

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•It is sometimes difficult to get the occupants of a building to evacuate because of social inhibition and diffused responsibility.


•The tendency to adopt cues for behavior from others is well documented in fires in restaurants, other public assembly occupancies, and hotels. 4-11

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CASE STUDY: World Trade Center

•In their studies of occupant behavior in the World Trade Center towers 1 and 2 provided some compilations of the activities of occupants prior to beginning their evacuation, including the following: information received and sought, the sources of help used, and the single reason to begin evacuation. 4-12

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•As can be seen from the comparison of the activities in the two tables, the rank order of the activities is identical except for the activity “Fought fire or smoke.” It should be noted that World Trade Center 1 was struck by the aircraft at approximately 8:46:26 a.m. and survived 102:05 minutes, collapsing at approximately 10:28:31 a.m.


•World Trade Center 2 was struck at approximately 9:02:54 a.m. and survived 56:50 minutes, collapsing at approximately 9:59:04 a.m. 4-13

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•The information received and sought by the occupants of World Trade Center 1 prior to their evacuation activity is presented in Table 4.1.12, and the identical activity for the occupants of World Trade Center 2 is presented in Table 4.1.13.


•A comparison of these two tables indicates the most information given and sought was “Information about what had happened.” 4-13

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•An announcement is reported to have been made to occupants in World Trade Center 2 at 9:00 a.m. s follows: There is a fire condition in WTC 1. WTC 2 is secure. Please return to your offices. At 9:02 a.m., a second announcement was reported as follows: May I have your attention, please. The situation is in Building 1. However, if conditions on your floor warrant, you may wish to start an orderly evacuation. 4-13

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•Remember, as indicated previously, World Trade Center 2 was struck by the aircraft at 9:02:54 a.m. Obviously, these contradictory building wide announcements may have been interpreted by some occupants as instructions to stay. 4-13

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•A comparative examination of these two tables indicates that 26 percent of the occupants of World Trade Center 2 decided to initiate their evacuation from their observation of the fire and damage conditions of the situation following the aircraft strike in World Trade Center 1

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• It should be noted that an estimated 86 to 91 percent of the occupants in World Trade Center 2 initiated their evacuation before their building was struck by the aircraft. 4-14

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•The single reasons given by occupants of World Trade Center 1 to begin evacuating not specifically mentioned by World Trade Center 2 occupants were “Building movement,” “Saw debris,” and “Saw smoke.”

•The single reasons given by the occupants of both towers were “Afraid/felt in danger,” “Was told to evacuate,” and “Friends/ coworkers evacuated.”



•During evaluation, an individual may decide to leave the building—flight—or to use a portable fire extinguisher—fight. During this time, he or she is particularly susceptible to the actions and communications of others.

•Thus, the individual may mimic the behavioral reactions of observed individuals, resulting in mass adaptive or nonadaptive behavior rather than selective, individualized behavior.


Panic Behavior

•One concept always discussed following a fire in which multiple fatalities occur, such as the Beverly Hills Supper Club fire, is panic behavior. One classic definition of panic is a sudden and excessive feeling of alarm or fear, usually affecting a body of persons, originating in some real or supposed danger, vaguely apprehended, and leading to extravagant and injudicious efforts to secure safety.

Panic Behavior•According to this definition, panic is a

flight or fleeing type of behavior that involves extravagant and injudicious effort and is likely not to be limited to a single individual, but to be transmitted to and adopted by a group of people.

Panic Behavior•From simulation experiments, a panic-

type behavior reaction has been defined in the following manner: “A fear-induced flight behavior which is non-rational, nonadaptive, and nonsocial, which serves to reduce the escape possibilities of the group as a whole.”

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Documents

1 Human Behavior and Fire How one reacts during a fire is related to the role assumed, previous experience, education, and personality; the perceived threat