1. A person is guilty of a class B felony if he intentionally causes a catastrophe by any means and is guilty of a class C felony if he does so willfully.
2. A person is guilty of a class C felony if he willfully creates a risk of catastrophe, although no fire, explosion, or other destruction results.
3. A person who knowingly does an act which causes or which he knows is likely to cause a catastrophe, or assents to the doing of such act, is guilty of a class C felony if he willfully fails to take reasonable measures to prevent the catastrophe.
4. Catastrophe means serious bodily injury to ten or more people or substantial damage to ten or more separate habitations or structures or property loss in excess of five hundred thousand dollars.