In Boston, Massachusetts, a fire in the Cocoanut Grove nightclub kills 492 people.

Boston is the capital and most populous city of the U.S. state of Massachusetts. The city serves as the cultural and financial center of New England, a region of the Northeastern United States. It has an area of 48.4 sq mi (125 km²) and a population of 675,647 as of the 2020 census, making it the third-largest city in the Northeastern United States after New York City and Philadelphia. The larger Greater Boston metropolitan statistical area has a population of 4.9 million as of 2023, making it the largest metropolitan area in New England and the eleventh-largest in the United States.

The Cocoanut Grove fire was a nightclub fire which took place in Boston, Massachusetts, on November 28, 1942, and resulted in the deaths of 492 people. It is the deadliest nightclub fire in history and the third-deadliest single-building fire. The Cocoanut Grove was one of Boston's most popular nightspots, attracting many celebrity visitors. It was owned by Barnet "Barney" Welansky, who was closely connected to the Mafia and to Mayor Maurice J. Tobin. Fire regulations had been flouted: some exit doors had been locked to prevent unauthorized entry, and the elaborate palm tree décor contained flammable materials. The air conditioning system was filled with a flammable gas because of the wartime shortage of nonflammable Freon.