According to a message on the event's official web site, a severe thunderstorm hit Sonisphere festival in Pori, Finland this afternoon (Sunday, August 8) at approximately 4:00 p.m. Strong gusts of freak wind damaged the stages and knocked down tents and fences. Around 40 people were injured, two of them seriously, and are currently receiving treatment in hospital.Sonisphere festival series producer Stuart Galbraith said in a statement. "Our first thoughts go out to the injured people and we sincerely hope they will have a full recovery." The second stage was damaged beyond repair and to guarantee the safety of the audience, artists and crew the authorities closed the stage. The storm damaged MÖTLEY CRÜE's equipment, forcing the band's show to be cancelled. IGGY POP did play, performing an acoustic four-track set on the main stage, while the Sonisphere crew worked hard behind the scenes to dry everything out and make repairs to damage across the site. Having borrowed the kit from SLAYER, ALICE COOPER is performing a full set on the main stage and IRON MAIDEN will also perform a full set, going on stage at approximately 9:50 p.m. and playing until approximately 11:50 p.m. The police and city authorities have agreed to allow IRON MAIDEN to finish later than originally planned. "We're doing everything we can to ensure that the show can take place. The show will run so long as it can run safely," said Stuart Galbraith.