The Fire Chief shall investigate or cause to be investigated the cause, origin, and circumstances of every fire occurring in the city by which property has been destroyed or damaged. All fires of unknown origin shall be reported, and such officer shall especially make an investigation and report as to whether the fire was the result of carelessness, accident, or design. The investigation shall begin immediately after 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 in the city shall forthwith notify the State Fire Marshal and shall within one week of the occurrence of the fire furnish him or her written statement of all the facts relating to the cause and origin of the fire and such further information as he or she may call for.
(Neb. RS 81-506)