Bloody Saturday was June 21, 1919, the culmination of the Winnipeg Strike. After six weeks of striking, ten strike leaders from the Winnipeg Trades and Labour Commission were arrested on June 17. In response, a peaceful protest was held on June 21. June 21 is the 172nd day of the year (173rd in leap years) in the Gregorian calendar, with 193 days remaining. ... 1919 (MCMXIX) was a common year starting on Wednesday (see link for calendar). ... Crowd gathered outside old City Hall during the Winnipeg General Strike, June 21, 1919 The Winnipeg General Strike was Canadas most influential labour action. ...

Mayor Gray, the mayor of Winnipeg, read the Riot Act and gave the protesters half an hour to leave Market Square. However, hired police are reported to have started firing five minutes following the reading of the act.

This protest turned into a disaster as a hired police (the original police force was also on strike) rode through the crowd on horseback. It is unclear who started the fighting, but at the end of the day, 24 civilians were injured, 6 police officers were wounded, and two civilians were dead: one who died instantly from a gunshot wound, and one who died later in hospital due to gangrene. Five days later, with armed police patrolling the streets, the strike leaders called for the strike to end.