What is 3rd degree arson?

Third Degree Arson (R.I.G.L. § 11-2-4) is when a person knowingly causes, procures, aids or counsels or creates by means of fire or explosion the damage or destruction of any property of that person or another with the purpose to defraud an insurer. The punishment is imprisonment for not less than two (2) years nor more than twenty (20) years or shall be fined not more than five thousand dollars ($5,000), or both; provided, that if death occurs to a person as a direct result of the fire or explosion or to a person who is directly involved in fighting the fire or explosion, imprisonment shall be for not less than twenty (20) years.

In Massachusetts, the equivalent is Chapter 266. Section 10: Insured property; burning with intent to defraud. This is when someone willfully and with intent to defraud or injure the insurer, sets fire to, or attempts to set fire to, or whoever causes to be burned, or whoever aids, counsels or procures the burning of, a building, or any goods, wares, merchandise or other chattels, belonging to himself or another, and which are at the time insured against loss or damage by fire, shall be punished by imprisonment in the state prison for not more than five years or in a jail or house of correction for not more than two and one half years.