It shall be the duty of the Fire Department to investigate, or cause to be investigated, the cause, origin, and circumstances of every fire occurring in the city in which property has been destroyed or damaged in excess of $50. All fires of unknown origin shall be reported, and the officers shall especially make an investigation and report as to whether the fire was the result of carelessness, accident, or design. The investigation shall be begun within two days of the occurrence of the fire and the State Fire Marshal shall have the right to supervise and direct the investigation whenever he or she deems it expedient or necessary. The officer making the investigation of fires occurring within the city shall immediately notify the State Fire Marshal and shall, within one week of the occurrence of the fire, furnish him or her with a written statement of all the facts relating to the cause and origin of the fire, and any further information as he or she may call for.
(Neb. RS 81-506) (1973 Code, § 3-307)