Five common denominators that contribute to accidents/incidents have been identified through studies of "tragedy fires."

It is important for firefighters to readily recognize the following common denominators so that future tragedies in wildfires can be prevented:

• Most incidents happen on smaller fires or on isolated portions of larger fires.
• Most fires are innocent in appearance before unexpected shifts in wind direction and/or speed results in flare-ups or extreme fire behavior. In some cases, tragedies occur in the mopup stage.
• Flare-ups generally occur in deceptively light fuels, such as grass and light brush. Fires run uphill surprisingly fast in chimneys, saddles, gullies, and on steep slopes.
• Some suppression tools, such as helicopters or airtankers, can adversely affect fire behavior.
• The blasts of air from low-flying helicopters and airtankers have been known to cause flare-ups.

For more safety tips from the Federal Fire and Aviation Safety Team, visit its Six Minutes for Safety section at www.nifc.gov.