to or the serious illness (including mental illness) of a person, serious harm to the environment (including the life and health of plants and animals), serious harm to any building or other property, or a worsening of any such injury, illness or harm, or are likely to cause the death of a person. Investigations & carrying out of functions A fire and rescue authority may authorise in writing an employee for the purposes of section 45 of the Fire and Rescue Services Act 2004 (separate from authorisation under section 44 above, which is granted to all firefighters). An authorised officer may at any reasonable time enter premises: for the purpose of obtaining information needed for the discharge of a fire and rescue authority’s functions under section 7, section 8 or section 9, or if there has been a fire in the premises, for the purpose of investigating what caused the fire or why it progressed as it did. However, an authorised officer may not: enter premises by force, or demand admission as of right to premises occupied as a private dwelling unless 24 hours' notice in writing has first been given to the occupier of the dwelling. An authorised officer may not enter as of right premises in which there has been a fire if the premises are unoccupied, and the premises were occupied as a private dwelling immediately before the fire, unless 24 hours' notice in writing has first been given to the person who was the occupier of the dwelling immediately before the fire. An authorised officer may apply to a justice of the peace if he considers it necessary to enter premises, but he is unable to do so, or considers that he is likely to be unable to do so, otherwise than by force. If on an application a justice is satisfied that it is necessary for the officer to enter the premises, and he is unable to do so, or is likely to be unable to do so, otherwise than by force, he may issue a warrant authorising the officer to enter the premises by force at any reasonable time. An authorised officer may also apply to a justice of the peace if he considers it necessary to enter a dwelling without giving notice as required. If on an application a justice is satisfied that it is necessary for the authorised officer to enter the