[1] Until the September 11 attacks, the fire was the deadliest building collapse in American history,[1] although the Texas City Disaster of 1947 killed more firefighters overall.

The fire, which broke out at Warehouse 7 of the Nelson Morris Company at the Chicago Union Stock Yards on the 4300 block of South Loomis Street, was first reported on December 22 at 4:09 am.

[3] Twenty-one firemen, including Fire Chief James J. Horan, and three civilians were killed when one of the blazing buildings collapsed with them inside.

[1] Following Horan's death, First Assistant Chief Charles Seyferlich took command of the operations, diverting men from fighting the fire to search and retrieve the dead firefighters.

[1] A historical marker titled "The Fallen 21," affixed to the old Union Stock Yard Gate a short distance from the memorial, offers a description of the fire.