In Chapter 4, Riis recounts the story of a landlord whose tenements receive the nickname "Blind Man's Alley" on account of the fact that many blind, impoverished men come to find homes there. Riis quite clearly chooses to relate this story to his readership on account of the glaring situational irony it introduces:
"Old Dan" made a big fortune—he told me once four hundred thousand dollars—out of his alley and the surrounding tenements, only to grow blind himself in extreme old age, sharing in the end the chief hardship of the wretched beings whose lot he had stubbornly refused to better that he might increase his wealth.
In an ironic turn of events, the landlord who preys on blind men becomes blind himself later in life, still refusing to give up his wealth or help his tenants even as he sits on death's door. Riis includes this passage to further showcase the cruel excesses of the wealthy, juxtaposing it with the abject poverty that results from the business ventures of these wealthy landlords. Furthermore, this ironic passage makes the exploitative landlord into a debased and silly figure in the eyes of readers: he is so obsessed with wealth, but in the end, his wealth cannot save him from the fate of those he exploited.