Original sentence: In August, at the Big Valley Jamboree in Camrose, Alberta, Costner and the band were scheduled next on stage when a severe windstorm struck, collapsing the stage and stands on the main stage
Edited sentence: In August, at the Big Valley Jamboree in Camrose, Alberta, Costner and the band were scheduled next on stage when a severe thunderstorm struck, collapsing the stage and stands on the main stage