The Canadian embassy flag had been half-staff since July 1. According to https://www.canada.ca/en/canadian-heritage/services/half-masting-notices.html :
Updated Notice of half-masting
Masting period: From now until further notice.
Occasion: DISCOVERY OF REMAINS AT THE FORMER KAMLOOPS INDIAN RESIDENTIAL SCHOOL
Masting location(s): The flags on the Peace Tower in Ottawa and on all Government of Canada buildings and establishments across Canada.
Additional details: Notwithstanding Section 19, but pursuant to Section 16 of the Rules for half-masting the National Flag of Canada, the flags on the Peace Tower in Ottawa and on all Government of Canada buildings and establishments across Canada will remain at half-mast on July 1st, 2021, and until further notice.
That notice was originally dated May 30 when the 200-ish unmarked graves were found at the children's school near the indigenous residential school. But then another 600 were found at another school on June 24.