Nadalie Lightning was asleep, with her phone charging in another room, when her 15-year-old grandson tried calling her 18 times late at night.

She still has the texts he sent her, saying he was going to call the police.

"I have to live with that the rest of my life because I didn't hear it at 1 a.m.," Lightning said.

Hoss Lightning, of Samson Cree Nation, died in hospital over a week ago after two RCMP officers shot him in Wetaskiwin, Alta., a city more than 60 kilometres south of Edmonton.

On Saturday evening, about 150 people gathered in a field behind a pawn shop in Wetaskiwin where the teenager was shot. Some held signs, while others held photos of the boy. Candles were later lit for a vigil, as an honour song rung through the area.

At dusk, people gathered around a memorial: a semi-circle of tealight candles glowed against a few stuffed animals and a bouquet.

"I'm broken-hearted," said Lightning.

"I'm hurting. We all are … I just want people to remember his face. What happened to him shouldn't have happened."

RCMP reported Hoss Lightning missing in early August. Several weeks later, in the early morning of Aug. 30, he called 911 for help, alleging he was being followed by people who wanted to kill him.

An RCMP officer found the teenager in Wetaskiwin with a machete and knife in his possession. After a conversation, he handed over the weapons and gave information to the officer.

The Mountie determined the boy was at risk and tried to arrest him and search him and the backpack he carried. But he ran away; the officer followed in their cruiser. More officers helping with the call arrived.

The teen was found in the field. Police approached him and exited their vehicles, but a "confrontation" ensued that led to two officers firing their guns.

The Alberta Serious Incident Response Team (ASIRT), the province's main police oversight agency, is investigating the shooting. The agency investigates instances where police action may have seriously injured or killed someone, as well as serious allegations of police misconduct.

The RCMP say they have initiated an internal investigation, separate from the ASIRT investigation.

The shooting shocked the community, stoking fear in some residents. Some people were left with unanswered questions about what happened.

The family, including cousin Izaiah Swampy-Omeasoo, is calling for greater mental health supports.

"He was a prime example of how trauma is still alive and well in our communities," Swampy-Omeasoo told CBC News. He also serves on the Samson Cree Nation council

"We don't need to draw the gun right away," he said. "Let's change our approach."

Hoss Lightning had stayed in group homes under Child and Family Services for months before the shooting, often running away, his grandmother said.

They frequently kept in touch, though, and he told her every day that he loved her, Lightning said.

She will remember her grandson as a kind, social person, who was in touch with his culture. He performed sundance last year, but couldn't this year, Lightning said.

She recalled when Hoss Lightning was three years old, they had a wiener roast. When the fire started, he ran up to the flames and started smudging, she said.

"He was that boy," she said, adding that he was curious and wanted to learn more.