Malfunctioning fireworks veered into the stands at a crowded Utah football stadium and struck members of the audience during a Fourth of July celebration, sending up to six people to the hospital, according to authorities and the event organizer. The accident occurred during the opening ceremonies of the Stadium of Fire show, the flagship event at Provo's annual Freedom Festival at LaVell Edwards Stadium on Brigham Young University. Organizers halted the show for about 15 minutes while injured audience members received medical attention, said Freedom Festival spokesperson Emory Cook. Six people were taken to the hospital, Cook said, but the number struck by fireworks and the severity of their injuries was not immediately available. The cause of the mishap — which involved fireworks shot off inside the stadium as several jets passed overhead — is under investigation by local authorities. Videos posted on social media show individual fireworks veering off from the cluster sent into the sky over the field and landing among rows of spectators in the stands at the outdoor arena. About 45,000 people attended the sold-out show, Cook said. Fire department personnel and paramedics were on scene when the show started and were able to reach the injured audience members within a minute, said Provo Fire and Rescue spokesperson Jeanie Atherton. She said her department transported only one person to the hospital but that other victims might have gone by personal vehicles. The fireworks that malfunctioned inside the stadium were relatively small compared to the large pyrotechnics that are used during the show’s finale, Cook said. Those larger fireworks are kept outside the stadium, he said. Following the accident, the BYU Police Department allowed organizers to proceed with the event, which featured the Jonas Brothers, KUTV reported.