The public owns it. I think the building that burned down was a house converted to apartments. I don't think it was "government housing," but I could be wrong. It could be that it was government housing in that the occupants were eligible for rental assistance (voucher), but that housing is actually privately owned and managed. But I have spent a great deal of time in large public housing developments and they are not ideal. Some aren't too bad but too many of them are substandard. It's an underfunded program and obviously, considering the homeless situation, we need better solutions. The private market is not meeting the need of the public.

If the entire book covers "the state" owning everything, then you should be able to find a quote from the book saying that.

My reading of Marx is that the public owns it, not the state. The government doesn't own federal lands, we the people own federal lands. What happens on federal lands is determined by policies created by elected officials. That's how public property is managed in a democratic republic. When I say "we" own it, that doesn't me that I get to go out on public land and do with it whatever I personally want to do with it. We all collectively own it and we manage it through our elected representatives. That's the only fair way to do it.

EDIT: Just read about the house in Philly. It was operated by the city housing authority and had passed inspections, including functioning fire alarms with good batteries. It's a horrible tragedy either way. Just note that weaponizing this example, out of many many examples of building tragedies is cherry picking though. For example, the building that collapsed in Florida was not public housing.