Holy shit @tobixen. That is a major mess. I hope the insurance company comes through for you. 5 washing machines, do you know if they all work? does the rent include water because if it does maybe they were taking advantage and doing laundry for a business? Thanks for sharing the photos. Sure gives a reality check on what had to be done.
Water is generally not metered in Norway and Oslo (it's possible to install a meter and pay less for the water, but it's hardly profitable compared to the installation job - in Norway water is cheap and plumbers are expensive), and no, they do not operate a laundry service :-)
Maybe one machine came with the house. The tenant upstairs had two machines, one wasn't working very well and should be thrown he said - so the tenants downstairs must have two or three machines, but it was only the youngest child at home yesterday and he wasn't quite sure.