At least 14 people were sent to the hospital Saturday after a storm knocked over concert entrance trusses at an Oklahoma outdoor concert venue hosting the Backstreet Boys and 98 Degrees, a spokeswoman for the property owner said.
The staff had begun evacuating fans in the venue after lightning was spotted, Kym Koch Thompson, a spokeswoman for WinStar World Casino and Resort, said.
But about 150 people in line "did not heed staff's warnings."
Thompson said the area was pounded by heavy rain and winds as strong as 80 mph.
Linda Tesfatsion was waiting for the concert to start at the venue in Thackerville when the storm went through, she said.
"Hundreds of Backstreet Boys fans playing chicken with an Oklahoma storm right now. Giant metal entrance structure, portable toilets, blew over. A handful of people left in ambulances," she wrote on Twitter with a picture of the structure that fell.
She said she saw four people put on gurneys and taken away by ambulances. A few of the injured had bandages on their heads but were able to walk, she said.
The metal structure that fell was holding up a purple banner that read "The Colosseum at WinStar," she said.
Two of the people who were hospitalized have been released, according to Thompson.
Backstreet Boy Kevin Richardson tweeted, "unfortunately, due to damage sustained in the storm earlier this evening, we are unable to perform the show tonight. Safety is always #1. Keep your tickets because, Backstreet WILL BE BACK!"