Overwhelmed by spot fires in bone-dry pine needles and leaf litter at their feet, a Cal Fire captain and three firefighters retreated to a patch of bare earth on a Cobb Mountain ridgetop during the first hour of the voracious Valley fire on Sept. 12. But they were not safe for long in the fenced goat pen where they took refuge. The wind picked up, the spot fires multiplied and one man saw the flames “sheeting and swirling” across a nearby driveway. Then, a brush-covered slope “torched into a wall of flame,” according to Cal Fire’s first published report on...