Dickens satirizes the uncaring attitude of the wealthy by describing disasters in the slum as if they're public spectacles. In Chapter 16, when the narrator is enumerating the many perils of Tom-All-Alone's, they explain that:

Twice, lately, there has been a crash and a cloud of dust, like the springing of a mine, in Tom-all-Alone’s; and, each time, a house has fallen. These accidents have made a paragraph in the newspapers, and have filled a bed or two in the nearest hospital. The gaps remain, and there are not unpopular lodgings among the rubbish. As several more houses are nearly ready to go, the next crash in Tom-all-Alone’s may be expected to be a good one.

The "springing" (opening) of a mine is generally met with celebration, as it represents the source of new revenue for a community. That is quite the opposite of what's happening here; beds are "filled" in the nearby hospital with seriously injured people. These accidents don't cause "public outcry," however: instead, they are so commonplace that they only merit "a paragraph" in the newspapers. The tongue-in-cheek language of the "not unpopular lodgings" would seem very insensitive and inappropriate here, were it not for the overtly satirical tone of the passage. Even though it's satirical, Dickens asks the reader to take this situation seriously, as it seems no one else will.

The anticipatory language of "ready to go" strikes a chord between panic and pleasure, as the next disaster is inevitably forthcoming. By "a good one" here, Dickens doesn't mean the crash will be a good thing for the tenants of the "rubbish." The destruction of these houses might be a "good one" for the city as a place that shuns the poor and fears the houseless and destitute, but it's going to be a tragedy for everyone actually living there.