The state fire marshal, deputies of the fire marshal, the chief of any organized fire department of any municipality, whether such fire department is regular or volunteer, or any member of any such fire department who has been duly authorized by the chief thereof, shall enforce the provisions of this act and any rules and regulations adopted pursuant thereto. Such persons are authorized to make any investigations deemed necessary of any fire or explosion occurring within this state. Such persons shall make an investigation of any fire or explosion occurring within this state, or an attempt to cause any fire or explosion within this state, if there is reason to believe that the fire was of an incendiary origin or was an attempt to defraud an insurance company. In addition, the chief of any organized fire department of any municipality may designate other qualified persons to conduct such investigations in such municipality. In order to carry out such investigations, the state fire marshal and those persons designated by or authorized to be designated by this section shall have the right and authority at all times of day or night to enter upon or examine, in accordance with existing laws and regulations, any building or premises where any fire or explosion or attempt to cause a fire or explosion has occurred. Such persons shall make a written report of the findings of any investigation conducted pursuant to this section which shall be filed in the office of the state fire marshal.