Section 150.20. Arson in the first degree

1.  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.