The chief of the Washington state patrol, through the director of fire protection, shall keep on file all reports of fires made to him or her pursuant to this code. Such records shall at all times during business hours be open to public inspection; except, that any testimony taken in a fire investigation may, in the discretion of the chief of the Washington state patrol, through the director of fire protection, be withheld from public scrutiny. The chief of the Washington state patrol, through the director of fire protection, may destroy any such report after five years from its date.