Abstract: At approximately 5:00 a.m. on June 30, 2013, 19 employees of the Granite Mountain IHC (Interagency Hot Shot Crew) were involved in the suppression of the Yarnell Hill Fire left their ridgeline position that was in the black safety zone and descended through and into a box canyon with heavy, unburned chaparral type vegetation on the way to a second safety zone. As the employees entered the bottom of the box canyon extreme fire behavior driven by high winds generated from the outflow of an approaching storm cut off the employees escape route, creating an entrapment situation. The employees had no choice but to attempt to create a deployment site and to deploy their fire shelters. All 19 employees were killed in the fire that burned over their position.