Crew members ran for their lives when overhanging metalwork crashed onto a stage in a Toronto park Saturday afternoon , pinning and killing one man , authorities said . The collapse happened around 4 p.m. , one hour before spectators were set to begin streaming in for a concert by the alternative rock group Radiohead . Several people were on the stage at the time , preparing for the show , when scaffolding-like material towering about 50 feet above collapsed . `` Unfortunately , four people were hurt , '' Toronto police Constable Tony Vella said . `` The remainder of the people , when they heard the stage coming ( down ) , ran from the area . '' Firefighters arrived to find one man `` trapped under the structure , '' said Toronto fire Platoon Chief Tony Bellavance . They helped to extricate the man , then moved away from what was then still considered an `` unstable structure , '' Bellavance added . Paramedics , who happened to be at the scene in preparation for the concert , `` immediately rendered aid , '' according to on-site Toronto Emergency Medical Services commander Peter Rotolo . The victim -- who has not been identified , amid efforts to contact his next of kin -- was pronounced dead at the scene . Police said he was in his 30s . Another man who suffered serious injuries due to the collapse was transported to Toronto 's Sunnybrook Hospital , Ian McClelland of the city 's EMS department said . The 45-year-old man suffered a head injury that is n't considered life-threatening , according to Toronto police . Two other men with minor injuries were assessed and released , McClelland said . Aerial footage afterward showed that some metal framing -- some of it covered in a blue material -- crumpled on the stage , which was in front of a large grassy area . Some of the scaffolding-like material remained standing , reaching about 50 feet in the sky . The stage was being set up especially for the Radiohead concert , Vella said . At the time it came down , the weather was good with no storm rolling through or significant winds , added fellow police Constable Harrison Ford . `` The big question is how '' this happened , Vella said . `` And that 's something we will be working closely with the Ministry of Labor to determine ( the cause ) exactly , to prevent any future cases . '' Reports : Indiana State Fair stage where 7 died was inadequate . The gates were scheduled to open at 5 p.m. , allowing fans onto the concert grounds for the sold-out concert , according to CNN affiliate CBC . The show was canceled due to what the production company Live Nation Entertainment described as `` unforeseen circumstances . '' `` Radiohead concert canceled . There has been an incident , more details forthcoming , '' said a post on Downsview Park 's official Facebook page . The band was to be joined by the Canadian musician known as Caribou . The Toronto incident comes 10 months after metal scaffolding supporting stage lights fell onto a crowd of fans and workers as a storm swept through at the Indiana State Fair right before the band Sugarland was to perform . Seven died and more than 40 were injured . In February , the Indiana Department of Labor announced penalties totaling $ 80,800 following a worker safety investigation into the collapse . Sugarland 's lead singer says band not responsible for Indiana stage collapse .
Several crew were on stage when the top part of the stage came crashing down . Most fled unharmed , but 4 were injured -- including 1 pinned under the structure . The trapped man was extricated and pronounced dead at the scene . Radiohead was set to perform a sold-out concert in the Toronto park Saturday evening .