Help! Water coming from adjacent property

[Kyle McCorkel]

I just got a text from my contractor in a SFR that I just closed on a month ago. The property is one side of a duplex, so I share a wall with a different property and different owner. I have not met the owner yet.

My contractor texted and said there is a leak coming from somewhere in the other property, which is starting to come into my basement.  He knocked on the door and no one answered.  I just looked up the owner on public records, googled their name, and tried calling the last number associated with the name.  No answer.

What other options do we have here to find the owner and/or get the water shut off so the issue can be fixed and damage minimized? Time is of the essence! Thanks.