TORONTO — Investigators combed through the wreckage of a Toronto stage Sunday to determine what caused the structure to come crashing down ahead of a Radiohead concert, killing the band’s drum technician and injuring three other people.

The British band said it was devastated over the death of Scott Johnson, a U.K. citizen in his 30s who was trapped under the rubble and pronounced dead at the scene.

“We have all been shattered by the loss of Scott Johnson, our friend and colleague. He was a lovely man, always positive, supportive and funny; a highly skilled and valued member of our great road crew,” the band said on its website.

Toronto Police spokesman Tony Vella said a 45-year-old man hospitalized with a head injury was improving and his life was not in danger. The other two were treated at the scene.

Officials from the Ontario Ministry of Labor searched through the wreckage for clues to the cause of the collapse Saturday in Downsview Park.

The band said fans could get refunds for the cancelled show at points of purchase.