Big Mick (and others):
From the "historical marker" link cited above:

On December 24, 1913, area copper miners had been on strike for five months. The miners were fighting for better pay, shortened work days, safer working conditions and union recognition. That day, during a yuletide party for the striking miners and their families, someone yelled, "Fire!" Although there was no fire, seventy-three persons died while attempting to escape down a stairwell that had doors that opened inward. Over half of those who died were children between the ages of six and ten. The perpetrator of the tragedy was never identified. The strike ended in April 1914.

The Italian Hall was built in 1908 as headquarters for Calumet's benevolent society. The Society, organized along ethnic lines, encouraged and financially aided immigrants and provided relief to victims of hardship. Following the 1913 Christmas Eve tragedy, the hall continued to be used for nearly five decades. The two-story red brick building was razed in 1984. Through the efforts of the Friends of the Italian Hall and Local 324 of the AFL-CIO, the site of the building became a memorial park dedicated ot the people who lost their lives in 1903.

--Charlie Baum