Steelpaper
Sounds like the ‘broken window’ scam. A shop owner with large plate glass windows finds the windows smashed and a company that replaces windows is on their doorstep giving quotes to replace them.
I think the theft of the fire extinguishers and hose should be reported to the police as it may be happening in other buildings and businesses.
When the new ones are installed I would suggest checking for any registration or identifying number on each, and the Secretary keep that information for each extinguisher. They usually have a metal tag with the last inspection date on them but that can be removed.
If there is no registration number, maybe paint part of each extinguisher with some identifying information (without covering the safety information), and engrave the full address of your building on the metal part of the new hoses.
It might be a good time to investigate better security for your building, including CCTV?