Tarshis explains that the idea for I Survived the Great Molasses Flood, 1919, came from one of her readers. She admits that she had not previously heard of the disaster and initially expected it to be a lighthearted story. However, her research revealed the event’s true nature as a tragedy that resulted from corporate negligence. Tarshis emphasizes that the disaster was preventable—“caused by people who made bad decisions” (69)—and holds the company that owned the tank responsible for failing to protect the nearby community.

Tarshis describes the book as historical fiction, defining the genre by noting that “all the facts are true […] The ‘fiction’ part is the characters who are from my imagination” (69). She clarifies that while Carmen, Tony, and other characters are fictional, they were inspired by real people who lived in Boston’s North End. Many residents of the neighborhood at the time were immigrants, particularly from Italy, who had arrived during a major wave of immigration to the United States in the early 20th century.

The author reflects on the theme of immigration, acknowledging that some readers may be immigrants themselves or have family histories that connect them to that experience.