It is unlawful for any person to store fireworks of any class without first having made a written application for and received a permit for such storage to the chief of the fire department at least ten days prior to the date of the proposed storage. It shall be the duty of the chief of the fire department to make an investigation as to whether such storage, as proposed, will be of such a nature and character and will be so located as to constitute a hazard to property or to be dangerous to any person, and he shall, in the exercise of reasonable discretion, grant or deny the application, subject to such reasonable conditions, if any, as he may prescribe.