noticeable comment from firefighters in CA over the last couple of days ...

when the fire moves to dry canyons - ravines with steep walls, lots of dry grass and brush, and no water in the canyon - it is IMPOSSIBLE to fight the fire there. The firefighters are not even trying. The burning grass in the canyon creates a funnel effect, which strengthens the wind blast and increases the severity of the flames. The firefighters are skipping those locations, and trying to save structures in other lower-risk zones.

So one of the morals is - DON'T live, or build, near a canyon with a lot of dry grass and brush.