origin of a fire; source of a fire
Refers to the place or thing where a fire started, often used in fire investigation or news reports.
The fire department is investigating the origin of the fire.
The fire started from the kitchen stove.
火元 refers to the actual place or person where a fire (or scandal) originated, while 火種 refers to the smoldering spark or latent cause that has not yet fully ignited.
A native compound of 火 “fire” and 元 “source or origin,” denoting the place or cause from which a fire starts.