From Wikipedia: (This refers to the incident which my grandfather told my mother killed 111 servicemen.)
The Cocoanut Grove was a premier nightclub during the post-Prohibition 1930s and 1940s in Boston, Massachusetts, United States. On November 28, 1942, it was the scene of the deadliest nightclub fire in history, claiming a total of 492 lives (which was 32 more than the building's authorized capacity) and injuring hundreds more. The scale of the tragedy shocked the nation and briefly replaced the events of World War II in newspaper headlines. It led to a reform of safety standards and codes across America, and to major changes in the treatment and rehabilitation of burn victims internationally.
It was the second-deadliest single-building fire in American history; only the 1903 Iroquois Theatre fire in Chicago had a higher death toll, of 602. It was only two years after the Rhythm Club fire which had killed 209.