The State Fire Marshal may investigate an explosion or fire that occurs in any place where explosives or ingredients for explosives are manufactured, transported, stored, or used. The State Fire Marshal may investigate an explosion, accident, or fire if there is reason to believe explosives were involved. The State Fire Marshal may report the findings of an investigation under subsection (a) of this section to federal or State authorities: if the explosion or fire was a willful act, for criminal prosecution of the person causing the willful act; or if the explosion or fire was accidental, so that precautions may be taken to prevent similar accidents from occurring. In an investigation under subsection (a) of this section, the employees under the direction of the State Fire Marshal may enter the premises where the explosion or fire has occurred to: examine documents; or administer oaths to and examine witnesses and other persons concerned. The owner, lessee, or operator of the premises where the explosion or fire has occurred, or an agent of these persons, may not hinder the actions of an employee of the State Fire Marshal described under paragraph (1) of this subsection. The State Fire Marshal may collect a fee of $20 for inspection of the vehicle of an explosive hauler.