When you combine all of the slices of the Swiss cheese and their 19 holes, failure is not inevitable, but it becomes more difficult to avoid. When a sleepy fire awakens and becomes complex all within the space of a few hours, it taxes the infrastructure that has been put in place. A robust organization can be resilient in the face of adversity, recovering quickly from difficult conditions, possibly even compensating for 19 holes. But if the organization and decision making, affected in some cases by little sleep over the previous 48 hours, is stressed and tested beyond its limits, undesirable results are more likely to occur.
It is conceivable that if one or more of the issues, or holes, had not occurred, we would not be mourning the 19 members of the Granite Mountain Hotshots.
One thing we don’t know about the fatalities on the Yarnell Hill Fire is why, exactly, the 19 firefighters walked into what became a lethal firetrap in a canyon. Nothing in the reports shed much light on how that decision was made, or by whom. It seems counter-intuitive that experienced firefighters would leave the safety of a previously burned area and expose themselves to the fire as they walked through unburned, very flammable vegetation, especially after a warning had been issued over the radio about an approaching thunderstorm cell with strong winds.