Relatório do Acidente ocorrido no Incêndio Florestal de Yarnel Hill

IHC were in the green. Only the Granite Mountain crew was in the black, normally considered a
“safe” location, potentially leading others on the fire to have greater concern for people working
in the green than for the Granite Mountain IHC.
We considered what provided for the safety of all the other personnel: possibly distance from
the fire, mobility, ability to make sense of what the fire was doing and react appropriately, or a
combination of these factors. Members of the Blue Ridge IHC moved through the green all day
in areas that subsequently burned. It is conjecture, but possible, that their actions may have
assisted in saving the life of GM Lookout as well as preventing the Granite Mountain IHC’s
trucks from burning. Obviously, decisions to operate in the green are laden with a variety of
assessments of the relative risk of doing so.
We will never know for sure, but we wondered whether the Granite Mountain IHC’s decision to
hike through the green might have seemed to them to be a decision to operate in the green
just like everyone else. For the crew, this would have meant moving away from a safe location
at the time of day when the fire would be most active. Decision makers base such decisions on
what they know at the time and their assessment of the risks associated with various courses of
action.
Regarding their intended destination, the 0700 briefing on June 30 included identification of the
Boulder Springs Ranch as a safety zone. SPGS1 (who had just arrived the evening before)
described it as “bomb proof,” a label indicating the Ranch was not only a safety zone, but that it
seemed to be an especially good safety zone that could withstand extreme fire behavior.
Because identifying a safety zone requires judgment and is therefore subjective, firefighters
often know the actual effectiveness of a safety zone only in retrospect. If a fire never affects a
safety zone with firefighters in it, firefighters may never know whether it would have proven
safe. In this case, fire progression maps and aerial photos taken after the fact demonstrate that
the large Ranch was well prepared to act as a fuel break in the hills above Yarnell. Inside the
perimeter of the Ranch, the preparation and arrangement of the buildings proved effective to
minimize damage to the home, livestock, and other values on the property. For these reasons,
the label “bomb proof safety zone” seems to have accurately described the Boulder Springs
Ranch.
Escape Routes
Continuing from this previous point, the Yarnell Hill Fire also prompts us to think about the
connections that firefighters make between escape routes and safety zones. As noted above,
we believe the Granite Mountain IHC did not perceive their route as overly risky, or they would
not have taken it. Wildland firefighters should consider to what extent a strong vote of
confidence about the effectiveness of a safety zone might be interpreted as a strong vote of
confidence about potential escape routes for getting there. Conversely, is there some implied
measure of the safety along an escape route because it leads to a safety zone?
Yarnell Hill Fire Serious Accident Investigation 52