Section 150.20 - Arson in the first degree1. A person is guilty of arson in the first degree when he intentionally damages a building or motor vehicle by causing an explosion or a fire and when (a) such explosion or fire is caused by an incendiary device propelled, thrown or placed inside or near such building or motor vehicle; or when such explosion or fire is caused by an explosive; or when such explosion or fire either (i) causes serious physical injury to another person other than a participant, or (ii) the explosion or fire was caused with the expectation or receipt of financial advantage or pecuniary profit by the actor; and when (b) another person who is not a participant in the crime is present in such building or motor vehicle at the time; and (c) the defendant knows that fact or the circumstances are such as to render the presence of such person therein a reasonable possibility.2. As used in this section, "incendiary device" means a breakable container designed to explode or produce uncontained combustion upon impact, containing flammable liquid and having a wick or a similar device capable of being ignited. Arson in the first degree is a class A-I felony.