146 workers are killed in a fire at New York’s Triangle Shirtwaist Factory, a disaster that would launch a national movement for safer working conditions - 1911 (see poem)

A dynamite bomb destroyed a portion of the Llewellyn Ironworks in Los Angeles, where a bitter strike was in progress - 1910

21 Chicago firefighters, including the chief, died when a building collapsed as they were fighting a huge blaze at the Union Stock Yards. By the time the fire was extinguished 26 hours after the first alarm, 50 engine companies and seven hook and ladder companies had been called to the scene. Until Sept. 11, 2001, it was the deadliest building collapse in American history in terms of firefighter fatalities - 1910