Section 220.1. Arson and Related Offenses.

 (1) Arson.  A person is guilty of arson, a felony of the second degree, if he starts a fire or causes an explosion with the purpose of:

  (a) destroying a building or occupied structure of another;  or

  (b) destroying or damaging any property, whether his own or another's, to collect insurance for such loss.  It shall be an affirmative defense to prosecution under this paragraph that the actor's conduct did not recklessly endanger any building or occupied structure of another or place any other person in danger of death or bodily injury.

 (2) Reckless Burning or Exploding.  A person commits a felony of the third degree if he purposely starts a fire or causes an explosion, whether on his own property or another's, and thereby recklessly:

  (a) places another person in danger of death or bodily injury;  or

  (b) places a building or occupied structure of another in danger of damage or destruction.

 (3) Failure to Control or Report Dangerous Fire.  A person who knows that a fire is endangering life or a substantial amount of property of another and fails to take reasonable measures to put out or control the fire, when he can do so without substantial risk to himself, or to give a prompt fire alarm, commits a misdemeanor if:

  (a) he knows that he is under an official, contractual, or other legal duty to prevent or combat the fire;  or

  (b) the fire was started, albeit lawfully, by him or with his assent, or on property in his custody or control.

 (4) Definitions.  "Occupied structure" means any structure, vehicle or place adapted for overnight accommodation of persons, or for carrying on business therein, whether or not a person is actually present.  Property is that of another, for the purposes of this section, if anyone other than the actor has a possessory or proprietory interest therein.  If a building or structure is divided into separately occupied units, any unit not occupied by the actor is an occupied structure of another.