Arson, the criminal act of deliberately setting fire to a building or other property. Originally, it referred to the malicious burning of another's property. Today it also refers to the burning of one's own property in order to collect insurance. Several degrees of arson are recognized, with corresponding severity of punishment. For example, setting fire to an apartment house or residence is considered a graver offense than burning an unoccupied warehouse where the danger to human life is slight. If loss of life occurs, murder may be added to the charge of arson.