having stuff is not the same as taking care of stuff

Yesterday, the toilet got clogged and it got into a long unfaced hole that goes to the basement. Unfortunately, one housemate stuff is almost directly into that hole, in the water ran into the stuff. I told the housemate that it happened, and that they should check, and I can tell that they didn't. I know the person is here. How did I get stuck with such unwell people? How can you care about having stuff and not care about taking care of it? There's definitely something wrong with them.