Refers to a destructive fire, especially one that damages buildings or property. Not used for a controlled flame or a campfire.
Last night, the house next door caught fire.
The cause of the fire is still unknown.
A fire broke out because of a carelessly discarded cigarette.
A fire broke out in the neighborhood in the middle of the night.
The firefighters put out the fire.
Last year, the house next door was caught in a fire.
The factory caused a fire, and it turned into a huge commotion.
火事 is the general word for a fire regardless of cause, while 放火 specifically refers to a fire started deliberately as a crime.
looter at a fire; thief at a fire scene · opportunistic criminal during a crisis
ship fire; fire aboard a ship