The Triangle Shirtwaist Factory fire in the Greenwich Village neighborhood of Manhattan, New York City, on Saturday, March 25, 1911, was the deadliest industrial disaster in the history of the city, and one of the deadliest in U.S. history. The fire caused the deaths of 146 garment workers – 123 women and girls and 23 men – who died from the fire, smoke inhalation, falling, or jumping to their deaths. Most of the victims were recent Italian or Jewish immigrant women and girls aged 14 to 23; of the victims whose ages are known, the oldest victim was 43-year-old Providenza Panno, and the youngest were 14-year-olds Kate Leone and Rosaria "Sara" Maltese.

Manhattan is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is coextensive with New York County, the smallest county by geographical area in the U.S. state of New York. Located almost entirely on Manhattan Island near the southern tip of the state, Manhattan constitutes the center of the Northeast megalopolis and the urban core of the New York metropolitan area. Manhattan serves as New York City's economic and administrative center and has been described as the cultural, financial, media, and entertainment capital of the world.