NEW YORK (Thomson Reuters Foundation) - Ever since Melina Laboucan-Massimo learned her sister was found dead after falling 31 stories from a Toronto building under suspicious circumstances, she has awakened every morning at 4:50 a.m., the time the death occurred.

“It’s something I can’t stop,” she said. “It’s trauma. It just continues.”

The death of Bella Laboucan-McLean, which remains unsolved, has driven her sister to speak up for Canadians grieving and questioning the disproportionate number of aboriginal women murdered or missing.

The spate of deaths and disappearances has received heightened attention since Prime Minister Justin Trudeau launched an inquiry, a measure opposed by his predecessor.

It was the summer of 2013 when Laboucan’s family, who are Lubicon Cree from Northern Alberta, sought answers from police.

Investigators told them the 25-year-old’s death must have involved drug abuse, a theory about the young college graduate the family rejected.

“She was not a drug user,” Laboucan-Massimo said.

Drug use was only disproved, however, after the family insisted on full toxicology testing and had to wait some two years.

For Laboucan-Massimo, the investigation captured persistent stereotypes about indigenous people.

“Indigenous women’s lives are undervalued in Canada,” said Laboucan, who spoke this week at a panel entitled “Canada’s Shame” at a Women in the World Summit held in New York.

Canada’s Minister of Indigenous Affairs Carolyn Bennett, also at the event, said the panel’s title was fitting.

“It’s the truth,” she said.

Aboriginal people make up to 4 percent of Canada’s population but accounted for 16 percent of female homicides between 1980 and 2012, according to the Royal Canadian Mounted Police.

An estimated 1,017 aboriginal women were murdered over that period.

Advocates say the unsolved deaths and disappearances often involved marginalized women and reflect a lack of concern by Canadian authorities and leaders.

Many deaths were wrongly classified as suicides or drug overdoses or blamed on natural causes, they say.

Michele Pineault, whose 20-year-old daughter Stephanie Lane went missing in 1997, said she was shocked by the lack of interest by authorities in the case.

Six years later, her daughter’s partial skeletal remains were found on the property of a convicted serial killer named Robert Pickton, she said. Pickton had told police he had preyed upon prostitutes.

Of the 33 women whose remains were found on Pickton’s pig farm, a third were reported to be aboriginal women. Pickton killed for at least two decades before his arrest in 2002.

“I do what I do to raise awareness,” said Pineault, who regularly shares her story at public events.

“If I can help save a life, then my daughter’s death is not in vain,” she said.