The Triumph of Death, a painting (c. 1562) by Pieter Bruegel the Elder depicting life at the time of "The Plague," is currently maintained at the Prado Museum in Madrid.
While the plague had hold of cities and countryside, people saw death everywhere. Some thought living apart from everyone else would keep the contagion way. Boccaccio's Introduction to the Decameron provides a first-hand account:
There were some people who thought that living moderately and avoiding all superfluity might help a great deal in resisting this disease, and so, they gathered in small groups and lived entirely apart from everyone else.
Not everyone agreed with this approach. Boccaccio continues:
Others thought the opposite: they believed that drinking too much, enjoying life, going about singing and celebrating, satisfying in every way the appetites as best one could, laughing, and making light of everything that happened was the best medicine for such a disease; so they practiced to the fullest what they believed by going from one tavern to another all day and night, drinking to excess, and often they would make merry in private homes, doing everything that pleased or amused them the most.
Why did people decide to ignore their responsibilities?
This they were able to do easily, for everyone felt he was doomed to die and, as a result, abandoned his property, so that most of the houses had become common property, and any stranger who came upon them used them as if he were their rightful owner. In addition to this bestial behavior, they always managed to avoid the sick as best they could.
Was there anyone to enforce the laws?
And in this great affliction and misery of our city [i.e. Florence] the revered authority of the laws, both divine and human, had fallen and almost completely disappeared, for, like other men, the ministers and executors of the laws were either dead or sick or so short of help that it was impossible for them to fulfill their duties; as a result, everybody was free to do as he pleased.