expression, godan verb (-su), intransitive verb
be reduced to ashes; be burned to the ground
Literary or dramatic expression describing complete destruction by fire, often used in historical or wartime contexts.
戦火で街は焦土と化した。
The town was reduced to ashes by the war.
焼け野原 is a noun meaning 'burnt field' or 'devastated area', while 焦土と化す is a verb phrase emphasizing the process of becoming scorched earth.
Composed of 焦土 (scorched earth) + と (quotative particle) + 化す (to change into). The exact historical origin is uncertain, but the phrase follows a classical pattern for expressing transformation.