The Cocoanut Grove fire occurred on November 28, 1942, in Boston, Massachusetts, at the Cocoanut Grove nightclub. Known as one of the deadliest fires in United States history, it claimed the lives of 492 people. Contributing factors included overcrowding and flammable decorations. The tragedy led to significant reforms in fire safety regulations and building codes to prevent future incidents. It highlighted the need for rigorous safety standards in public spaces and had a lasting impact on fire safety legislation.