The plumber discovers that the refrigerator has been placed without a shut-off valve for the water / icemaker line, making it impossible to pull the fridge away from the wall without rupturing the line and spraying water everywhere.
Downstairs, this same water / icemaker line was installed with an illegal self-tapping saddle valve which pierces a main copper water pipe. These are not allowed in Minnesota (and a growing number of other states) because they are prone to leaks.
The plumber begins replacing all of the faulty copper water pipes in the house with pex piping, piece by piece.
He also adds a proper water shut-off valve behind the refrigerator.
Most of the new plumbing work is readily visible in the open walls of the downstairs bathroom.
A new silcock shut-off valve is installed in the mechanical room (instead of in a ceiling access panel), but not hooked up to the water main yet.