No, it's not the water heater (community boiler). It's only two years old. It's the pipe chunking apart from the electrolysis caused by the electrical system being grounded through the hot water pipe, which is galvanized steel. I had electrolysis corrosion, real bad, on the hot water valve underneath the kitchen sink, white and green powdery stuff with rust. None on the cold water side. Every once in a while, you see dirty water with large chunks of dark rust coming out of the bathtub faucet only on the hot water side. When I see that, I go, "Oh F*, somebody's gonna get it," and hope that it's not my turn. Usually, the water system goes down a few days later when the leak manifests somewhere.
I had to turn the carpet back like that because I needed my furniture to be put back so I can actually LIVE again and had gone through the carpet taking THREE WEEKS TO DRY the first time. F* that.
Never again. I'd rather live out of my Jeep and take showers at my store's shower facility than have to go through this again.
Edit: Look at the counter top photo again. What you need to see is that the counter top is warped and has a (?) bowl-like roll from front-to-back and indicates that the particle boards is ruined. There are chunks of the particle board coming off the underside edge in front of the sink. I have suggested to my neighbors that someone tell the man to SELL THIS PLACE so they can raze this place. It's going to cost him more to fix these problems than it would to raze and rebuild. Hell, I'd sell out and retire. He is already wealthy to start with.
And I should mention that the carpet is a non-issue in regards to damage from me, since they are converting from carpet to tile one-by-one on all the bottom units. It WILL be tossed, leak or no leak.