The executive director of Cisco Ottawa Bluesfest says they'll review how they determine when to call off a show because of bad weather after strong winds toppled the festival's main stage at Lebreton Flats Sunday night, sending three people to hospital.

"We were monitoring the weather and what was a watch turned into a more severe situation and when that happened we called it immediately," said Mark Monahan, executive director of the festival.

"We deal with weather every day and you know we don't automatically call a show because we have weather we see coming in. If we did that, we wouldn't be able to run a festival."

Environment Canada issued a severe thunderstorm watch for the City of Ottawa at 6:09 p.m. Sunday. A warning was issued at 6:35 p.m. The weather agency indicated the storm was capable of producing 140 kilometre per hour winds and would hit the city between 7 and 7:30 p.m.

The storm whipped through Lebreton Flats at about 7:20 p.m., blowing down the MBNA stage. Ten people were treated by paramedics; three were sent to hospital.

"What we've been told at the weather office and so on was that it was a very unusual situation. I mean the fact that it brought that stage down and nothing else in the park was just a freak situation," Monahan told reporters at a news conference on Monday.

The stage is not owned by Bluesfest, but is rented from an outside company. It's the fifth year the festival has used the stage and Monahan says it was inspected by an independent structural engineer when it was constructed at the site.

"The stage is put up according to specs and there is an engineer who inspects the stage. That's all I can really say and that was done again this year," said Monahan.

Injured released from hospital

Hospital officials told CTV Ottawa Monday that all three people who were sent to hospital after the stage collapsed have been released.

Paramedics initially told reporters one man suffered life-threatening injuries when something pierced his abdomen.

However, hospital officials say the man's injuries were not life-threatening when he arrived at the emergency room and he was released from hospital five hours after being admitted.

That patient has been identified as Sandy Sanderson, a truck driver for the band Cheap Trick. The classic rock band left the stage moments before it collapsed. They had just finished playing their hit ‘I Want You To Want Me'.

Cheap Trick describes storm

The band posted video of the damage on its website on Monday. The video shows lead singer Robin Zander realizing the band's driver was injured.

"Is that our driver? Is that our driver?" Zander asks as he moves towards paramedics.

"You just get better and get back."