Alright, thanks, ***** ***** explains the issue.
The plumber was clearly negligent for opening up a pressurized water pipe/fixture without first confirming where the water shut-off valve was for that fixture as well as the main water shit off valve for the whole unit. And because the plumber was the agent of the property/unit owner and working at the owner's direction, the owner is legally liable for the negligence of the plumber under the legal theory of Respondeat Superior.
As a consequence, you may sue both the plumber and the upstairs owner for the damages that have been done to your property----both those covered by the deductible and those covered by the insurance company.
One very important thing to be aware of is that only one suit may be filed against the owner and or plumber and because you used insurance, your insurance company is subrogated to your right to sue to the extent that they paid for damages. This means that both you and the insurance company may legally sue the plumber/owner. So, before you file suit, be absolutely sure to give notice to your insurance company written notice of your intent to file suit and invite them to retain an attorney to join you in your suit---or to give you permission to sue on their behalf to collect the damages that they are owed---in addition to your $1000 deductible that you are entitled to collect back.
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I wish you and yours the best this holiday season,