Toronto's Danforth Avenue shooting victims have launched a class action lawsuit against US gun maker Smith & Wesson.
A statement of claim filed in a Canadian court alleges the gunmaker was negligent for not incorporating "smart gun" technology in the firearm used in the shooting.
The proposed class action is seeking C$150m ($114m; £87m) in damages.
Two people were killed and 13 injured in the attack on 22 July, 2018.
Smart gun technology prevents unauthorised users from firing a weapon by using different forms of identification, like finger or palm prints, or other locking devices.
The statement of claim filed at the Ontario Superior Court on Monday says Smith & Wesson had agreed to incorporate smart gun technology into its new weapons in 2003, and was aware that thousands of handguns are stolen each year.
The 40 series, introduced in 2005, did not include that technology. That includes the M&P40 semi-automatic pistol used by the shooter, Faisal Hussain.
His Smith & Wesson firearm was stolen. He shot at restaurant patrons and pedestrians outside on a busy street in Toronto's Greektown district on a summer evening.
Hussain killed himself following an exchange of gunfire with police. He was not licensed or authorised to use a firearm.
"[The] defendant knew the handgun was an ultra-hazardous product that posed a substantial likelihood of harm to the public," says the statement of claim
"In the circumstances, [the] defendant owed a duty to the Class to ensure that any handguns it made available to the Canadian market were designed and manufactured to implement technology that would prevent unauthorised users from causing the very type of harm and injury suffered by the Class members."
Smith & Wesson, which is based in Springfield, Massachusetts, has yet to comment publicly.
A judge must still decide whether the suit should proceed as a class action. None of the claims has been tested in court.
The court filing also notes that the US Congress passed legislation in 2005 that grants broad immunity to gunmakers from civil actions resulting from the misuse of their products - but Canada has no such laws.
Still, there is at least one lawsuit in the US against a gun maker whose product was involved in a mass shooting.
The families of victims of the Sandy Hook school shooting, in December 2012, filed a lawsuit against Remington Arms five years ago, saying it should be held liable.
That lawsuit is scheduled to go to trial in September 2021.