A contract is a two way street.

She avoided the sketch streets and drove me the same way by this lake and all the nice homes.

I want to see the lots and make sure everything is good with them, because there are people dumping garbage on some lots, others are sneaking in and chopping down trees and selling the wood, others are cooking drugs, etc. 

There is a two story structure in the front of the property facing the street with units 1 & 2 on top of each other, and the other part of the house (an addition) is perpendicular to that with 2 stories.

Its a 5 bed/3bath, 2300 (+basement) SFH on .48 ac and is across the street from the hospital in a nice part of town.

Streets in front of property should be handled by HOA, and then on your driveway and walkways/decks it is wise to hire a service or a neighbor that can do this on demand when snowfall happens.

The fire dept turned off the water at the street by the time our guy got there, and the City quickly got involved exerting a fair amount of pressure.In the interests of keeping this story short, these are all the things that we had to do: Communicate with the property owner, the tenants, and the city constantly, offer hotel rooms to affected tenants (some took us up on this), secure the building from future squatters, get the water main and all pipes thawed out, have the water company turn the water on at the street, have a crew of plumbers isolate and repair/replace broken pipes in a muddy crawl space, clean up the mess created by the water in the basement/crawl space, get into all apartments to inspect for damage, test and get water service restored, and repair some internal damage to one of the apartments (that's still in progress), and apologize to the tenants. 

There are not duplexes on our street, but two streets over there is a mix.

You can't make the argument that it is because of the floor plan, busy street, etc. because for the right price someone would buy it. 2.

As you mentioned, if it was the sewer line from the house to the street, you would expect both toilets to have an issue.