The main stage collapsed at Cisco Ottawa Bluesfest Sunday night around 7:20 p.m., moments after Cheap Trick members left the stage due to an intense storm.
OBJ editor Peter Kovessy saw the stage fall, leaving it torn apart, with the canopy blown across the field just in front of the stage.
Wind gusted under the canopy like an umbrella and toppled it, leaving behind a wreck of fabric and twisted metal.
Some members of the crowd fled into the adjacent Canadian War Museum, where they were initially instructed to evacuate to the parking garage. They were ultimately ushered off the site.
"Fire crews and police are checking beneath stage and so far no one found. Appears everyone made it out safely," the Ottawa fire service wrote on Twitter just before 8 p.m.
Twenty minutes later, the service wrote a second search underneath the canopy confirmed nobody was trapped.
On Twitter Sunday night, Bluesfest officials said no serious injuries occurred as a result of the collapse, and that remaining programming for the festival was cancelled.
In a Facebook update, Cheap Trick said no one in the band was hurt. "Everyone is okay and we are so lucky to be alive and hope that all the fans are okay too," read a caption underneath a picture of the damaged stage.
Environment Canada issued a thunderstorm warning for Ottawa Sunday evening, saying winds were averaging 90 kilometres per hour and gusts were possible of up to 140 kilometres an hour.
The storm also downed trees and periodically knocked out power across Ottawa.
Bluesfest draws an average of 250,000 people during its run. Sunday was the closing night of the 12-day festival.
- With reports from Peter Kovessy