Triangle Waist Company, often called the Triangle Shirtwaist Co., manufacturers of women's cotton and linen blouses. Located in lower Manhattan in the early 20th cent., on Mar. 25, 1911 it was the site of New York City's worst factory fire. The company, which occupied the top three floors of the 10-story Asch Building, employed some 500 young seamstresses, mainly Jewish and Italian immigrants, and less than 100 men. The fire began on the eighth floor at about 4:45 descr='[PM]'; fed by burning cloth, it became a conflagration. Although hindered by inward-opening doors that slammed shut in the crush, most of those on the eighth and tenth floors managed to escape, but on the ninth the rear door, bolted to prevent theft, could not be opened, and after the fire escape collapsed most were trapped. Clothes and hair ablaze, many women jumped to their deaths. Fire companies could do little, as neither water from their hoses nor their ladders reached above the seventh floor and their safety nets ripped with the weight of so many. In less than 15 minutes 146 died, nearly all women.

The company's owners were tried for manslaughter, but acquitted (1914), and their liability was limited to $75 in damages paid to 23 of the victims' families, awarded after a civil suit. The outcry occasioned by the fire, however, led to important reforms. The Factory Investigating Commission (headed by Robert F. Wagner and Alfred E. Smith), the Bureau of Fire Investigation, and the Fire Department's Fire Prevention Division were all established later in 1911. The ultimate result of their investigations were new labor, health, and fire safety laws, which, among other things, mandated outward-opening doors, sprinkler systems, fire drills, and regular building inspections, and forbade locked doors during working hours. The fire also led to increasingly successful labor-union organizing in city factories and sweatshops, particularly by the International Ladies Garment Workers Union and, more broadly, to a liberal and reformist movement within the Democratic party.

See L. Stein, The Triangle Fire (1962, repr. 2011); D. Von Drehle, Triangle (2003).