A 13-year-old girl died in hospital Tuesday, three days after being struck in the head by a puck during a game between the Columbus Blue Jackets and Calgary Flames.
Brittanie Cecil, who would have turned 14 on Wednesday, was hit by a shot early in the Blue Jackets' 3-1 victory.
It is believed to be the first time a fan has been killed by a flying puck in the 84-year-old history of National Hockey League.
The puck came off a slapshot that was deflected by a defenceman, then sailed over the end glass into the stands at the Nationwide Arena in Columbus.
The Blue Jackets, in a statement released on Tuesday, said the club was "deeply saddened by the tragic accident."
"Our thoughts, prayers and condolences go out to Brittanie's family and friends during this time of anguish," the statement said. "Our fans mean the world to us and this loss has had a profound effect on the entire Blue Jackets family."
NHL Commissioner Gary Bettman also expressed grief at news of the accident.
"Our fans are our family, and this tragic accident fills us all with a deep sense of sorrow," Bettman said. "We extend heartfelt condolences to the grieving family and friends on this day of profound sadness."
NHL spokesman Frank Brown said he could not recall any other fan being killed by a puck at an NHL game.