N.D. Cent. Code § 18-01-07

An investigation of each fire must be made by the officers required to report the occurrence of fires under section 18-01-06. When the state fire marshal deems it expedient or necessary, the state fire marshal may supervise and direct any of such investigations. Within thirty days after the occurrence of a fire, the officer investigating it shall furnish to the state fire marshal a written report containing a statement of the facts relating to the origin and cause of the fire and such other information as the state fire marshal may require. The state fire marshal shall have access to a record of all fires reported in the state together with the facts, circumstances, and statistics in connection therewith and showing the origin of such fires as the same may be determined from the reports.