This term is from Chris Theisen, firedog extraordinaire. It is both descriptive and accurate.
When you spend even a little time in the woods, it becomes evident that gravity is a force of nature which cannot be denied. Things fall to the ground in myriad ways. During a fire, trees burn at the roots or partway up the trunk. They can burn from the inside. The organic material in the soil can burn, leaving the roots with less to hang on to. Conifers are shallow-rooted, so it doesn’t take that much to cause them to succumb to gravity.
Snags–standing dead trees–scare me much more than the fire itself. Snags can fall silently, hitting the ground in an explosion of wood. Or they creak and tip slowly. Live trees can fall too. Hearing this sound makes me uneasy, gives me a little squirt of adrenaline. When you walk through the woods, there are tons of material over your head. Most of the time we count on that vegetation to stay up there. All that changes when there has been a fire. Falling snags kill Forest Service employees every year.
Death from above will keep this part of the Pacific Crest Trail closed until next summer. We fervently hope that winter storms will bring down a lot of the dangerous trees when no people are around. We will have to carefully evaluate the safety of working in that area before we re-open the trail.