EDMONTON -- Alberta teachers were asked to wear orange on Monday in remembrance of 215 Indigenous children whose bodies were found buried beneath a former residential school in B.C.

The Alberta Teachers Association put out the call on Sunday as a sign of remembrance and commitment to truth and reconciliation.

Orange is the colour chosen to symbolize the spirit of reconciliation

The ATA also lowered the flags at its headquarters at Barnett House in Edmonton to commemorate the discovery of the remains of 215 children at a former residential school in Kamloops, B.C.

The Tk'emlups te Secwepemc First Nation said Thursday the children's remains were confirmed the previous weekend. 

Chief Rosanne Casimir called the discovery an “unthinkable loss that was spoken about but never documented at the Kamloops Indian Residential School.”

She said it's believed the deaths are undocumented, although a local museum archivist is working with the Royal British Columbia Museum to see if any records of the deaths can be found.

'OUR HEARTS ARE BROKEN': MAYOR

Like the ATA, Edmonton Public Schools will lower flags to half mast until after National Indigenous Peoples Day on June 21.

And starting Monday, the flags at Edmonton City Hall will be lowered for 215 hours, until June 8. Council will observe a moment of silence 215 seconds long.

"Our hearts are broken at this shameful discovery that is clear evidence of what happened at residential schools, the thousands of children who didn't come home, and people in our communities are just devastated," Edmonton Mayor Don Iveson said Monday, speaking after a Big City Mayors' Caucus meeting. "(People) fom all walks of life, including your mayors." 

Asked about the future of landmarks who are titled after city builders who were involved in racist policies, Iveson said the city would continue to review its infrastructure naming process. 

"There are a variety of these questions coming forward around historical figures with implicated roles in, this case, cultural genocide, so I think we want to look at the overall context of that naming policy and also seek input from community." 

Edmontonians paid respects in a number of ways over the weekend. Some wore orange, at least 215 pairs of shoes were laid out at a Catholic monument, and a memorial was started at the Alberta legislature.   

Flags were also lowered across the province, from Red Deer to Calgary. 

Contact the Indian Residential School Survivors Society toll-free 1 (800) 721-0066 or 24-hour Crisis Line 1 (866) 925-4419 if you require further emotional support or assistance.

With files from The Canadian Press