To me the classic example is the ancient frozen pipe thread, or worse, broken off at the joint.

It seemed very strange because I did a test with a pressure gauge and there was no plumbing leak, and the ground is very, very frozen outside so it shouldn't be seepage from outside.

When you inherited the property, the equity in that property represented what the cost of that property was because what you inherited in that equity was just another gifted form of cash...frozen, but still a form of cash, and thus a cost to you. 

Juice boxes, wine, melting frozen pops, magic markers, trails of Cheerios, secret stickers, and vacationers who leave their common sense at home have caused more trouble.

My only concern left would be with frozen pipes.

We had a broken water pipe (old, not frozen) in 2019 that caused $12,000 in damages.

Also concerning from our perspective as a landlord if there was a true emergency like a major plumbing leak or furnace failure (frozen pipes) that could cause significant damage if not addressed quickly.

They then got mad at me,  stopped paying and then moved out leaving me a few months short.Tenant 3 was in within a few weeks but in the time of them moving in to having to pay 2nd months rent all their assets had been frozen and the previously cleared rent check had been clawed back by their bank.  

No more than taking selfies is "modeling" or heating up a frozen pizza is "cooking."

If you rent them out be prepared to handle freezing cold weather and frozen pipes, a big problem with them.