A helmet could have saved the life of a cyclist thrown by a truck in Rosemount last summer, according to the coroner’s reports.

Justine Charland St-Amour was killed Aug. 22, 2016 at the corner of Iberville St. and Rosemont Blvd.

Both the 24-year-old cyclist and the 10-wheel truck stopped at the same red light. When it turned green, Charland St-Amour went straight as the truck turned right.

According to coroner Dr. Gilles Sainton, speed wasn't a factor. He noted it was very busy at the time and that police officers said the truck driver likely had reduced visibility.

The truck hit the cyclist with its back wheels and she was thrown from her bike, suffering serious head trauma and causing her death.

Charland St-Amour was not wearing a helmet and therefore the coroner ruled her death as preventable and an accident.

Charland St-Amour’s mother said that she is angry Sainton noted in his report that the truck was making an illegal right turn when the driver hit the woman, but did not blame this on her death.

"If he didn't turn right, none of this would have happened. That's not an accident," said Martine Charland.

"I want the world to know that not respecting road signs can have terrible consequences."

Marc-Andre Gadoury of the city of Montreal said the signage was changed before the collision, so does not understand why the driver is not blamed for causing Charland St-Amour's death.

"We've changed the sign at the intersection. Now it's the right of way for pedestrians and cyclists. So we acted before the coroner's report, but then to see the blame on the truck is partial it's hard to understand," said Gadoury.

Charland is, however, grateful that the cause of death is finally known.

"In some ways it's reassuring. We never knew exactly what happened. Now we know," said Charland.

Sainton went on to say Charland St-Amour’s death should bring into question the mandatory wearing of helmets, but noted that instead, the city has chosen to use awareness campaigns and allow citizens to decide for themselves.