People are reacting to a mass shooting in Nova Scotia that has sent shockwaves of grief across Canada and the world.

A gunman went on a 12-hour rampage that began late Saturday in the small community of Portapique, killing at least 18 people in one of the worst mass killings in Canadian history. The victims include an elementary school teacher, two health-care workers, a family of three and an RCMP officer, among others.

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