The great mass of workers within urbanized areas lived in slums - heavily populated parts of a city marked by filth and squalor. Housing structures were known as tenements; run-down apartments buildings of four to six stories, usually housing four families on each floor.
Overtime many multi-room apartments were boarded off to become one room apartments. Leaving families, and oftentimes strangers, to cook, eat, and sleep in the same room. Disease often flourished in such cramped and often airless quarters, and fire was an ever present danger.