there are many situations that could cause this event and all of them are scary and destructive. You have painted varying possibilities in my mind. Very well done in a few short lines.
I'm not very good with super short forms, but this is a clever little write. "Built from the dead of the land" is a really good line and the poem does create a small but perfectly formed portrait. You can definitely see the fiery image in your head. It's really difficult to be this brief but still be meaningful. The "dead of the land" reference makes us think of the fire as a form of renewal, of cleansing, removing the dead, and then that positive inference is contradicted by "out of control". Fire is our life, our warmth, our cleansing, but also, our greatest fear.
I like "susurrous", it must be related to "susurration", which I THINK means, a sort of whisper or moaning sound which rises and falls.... really musical word and great audio imagery in relation to a fire. :-)