Torrential rain threatened to wash out the Fire Aid for Fort McMurray benefit concert Wednesday, answering the event slogan of "the show goes on rain or shine... we're praying for rain."

Concert-goers who lined up outside Edmonton's Commonwealth Stadium scattered in a sudden downpour, but returned with the sun to flood the arena. Many sported precautionary parkas over shirts with slogans such as 'Alberta Strong.'

Stetson hats bobbed through the crowd, cowboy boots slapped on the wet ground, and fringed festival vests offset black leather jackets in a sea of fans. It was an eclectic mix of fashion that reflected the range of genres covered by 16 different artists and bands.

Organizers braced for more than 30,000 attendees, and said they hoped to match a similar benefit concert in 2013. Flood Aid raised $2.3 million for victims of the flooding in Southern Alberta three years ago.

Nickelback headlined the concert, wrapping up on acts by groups such as City and Colour and Blue Rodeo.

But concert-goers said the music was just a small part of why they braved thunder and lightning.

"As an Albertan I feel like I'm supposed to be here," said Brooklyn Copithorne, who donated clothes and food when waves of evacuees first came to Edmonton.

Eleven-year-old Cory Grace also braved his bedtime to stay until the end of the concert.

"They're a part of our province," he said about Fort McMurray. "They're important to us and they need to know that we're supporting them."

Grace wrote his support onto a message board set out for concert-goers to sign. He couldn't fit everything he wanted to say into one pocket of empty space on the poster.

"But I would say I'm supporting them and we're still following them and we're still trying to help out and that you're welcome to stay here," Grace said. Cory Grace, 11, says his school welcomed young evacuees from Fort McMurray last month and he wanted to show his support for new classmates at the concert.

Others added their own messages of support, or simply drew hearts.

​"Stay strong and don't give up," said Sapphire Picard, who wrote on the board with her elementary school friend.

"Stay strong, you guys have made it so far already that you'll get through it," said Danaka Hill.

"Just keep smiling and you're going to be great, keep your heads up," added Brooke Baxandall.

Proceeds from Wednesday's event will go to The United Way of Fort McMurray to help rebuild after 'The Beast' wildfire.

@ZoeHTodd