One person was killed and another seriously injured in a stage collapse before a Radiohead concert that was expected to draw 40,000 people today in Toronto, police said.
Two other people were treated for minor injuries at the scene in Downsview Park," Police Constable Harrison Ford said.
All the victims are believed to be crew members who were setting up the stage, he said.
The stage was still being set up for the outdoor concert when the collapse occurred, and the band was not on stage. But thousands of people had gathered for the show.
The man who was killed in the collapse was trapped under the rubble, Emergency Medical Services deputy commander David Viljakainen. The man, in his mid-30s, was pronounced dead at the scene.
"It was a crushing injury that killed the man," Fire Services Platoon Chief Tony Bellavance said.
The man who wa seriously injured was a 45-year-old who suffered a head injury, Viljakainen said.
Police spokesman Tony Vella said most of the crew members working at the time of the collapse were able to get out of the way in time.
"They were setting up when the top portion collapsed on top of them. Unfortunatly, four people were hurt," he said. "The remainder of the people, when they heard the stage coming down, ran from the area."
Radiohead tweeted that "due to unforeseen circumstances tonight's concert at downsview park tonight has been canceled. Fans are advised not to make their way to the venue."
Witnesses said it was not clear what caused the collapse, because there was only a light breeze.
"You could see there was a lot of heavy lighting, heavy sound systems draped across the top of the stage and there was a slight breeze, nothing that you would think would cause the stage to fall over, but there was that breeze," said Alexandra Halbert, who was working nearby in the park and had a clear view of the stage.
Fans arriving at Downsview Park as the collapse occurred said the scene was chaos.
"Nobody knew what was happening and what the extent of it was," said Chris Collins, who was in the parking lot when it happened. "But, then within a few minutes, we started to hear the sirens.
"To be honest it sounded like a roller coaster," he said. "You know so basically like a series of clacking noises and increasing in volume as the collapse proceeded."
He said he could see any obvious explanation for how it happened.
"It was just a beautiful in Toronto not windy, and it didn't seem to be weather related at all," he said.
The Associated Press contributed to this report.