OTTAWA - Veteran US band Cheap Trick escaped unharmed when a storm blew down much of the stage on which they were performing at a major rock concert in the Canadian capital Ottawa late on Sunday.

The band members were about 20 minutes into their set at the Ottawa Bluesfest when the storm suddenly swept over the area.

The band left the stage seconds before a particularly strong gust destroyed most of the structure, pushing it back onto an adjacent road and away from the thousands of spectators, according to eyewitnesses.

"It was just a freak situation," event organizer Mark Monahan told reporters on Monday.

He quoted paramedics as saying three people were injured, all of whom had left the hospital.

Government officials are investigating the incident, which happened on the event's final night.

"Fortunately the band and crew are all lucky to be alive and we'll see you down the road," Cheap Trick's lead vocalist Robin Zander said on the band's website.

Ottawa Mayor Jim Watson, who was present at the event, said he did not feel organizers could have prepared for the strength of the storm.

"It's Mother Nature, really, and there are certain things you just can't plan for. ... We're very fortunate there was no one killed," he told the Canadian Broadcasting Corp. on Monday.